Compositions and methods for control of insect infestations in plants

ABSTRACT

The present invention is directed to controlling pest infestation by inhibiting one or more biological functions in an invertebrate pest. The invention discloses methods and compositions for use in controlling pest infestation by feeding one or more different recombinant double stranded RNA molecules to the pest in order to achieve a reduction in pest infestation through suppression of gene expression. The invention is also directed to methods for making transgenic plants that express the double stranded RNA molecules, and to particular combinations of transgenic pesticidal agents for use in protecting plants from pest infestation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Nos.60/560,842, filed Apr. 9, 2004, 60/565,632, filed Apr. 27, 2004,60/579,062, filed Jun. 11, 2004, 60/603,421, filed Aug. 20, 2004,60/617,261, filed Oct. 11, 2004, and 60/______, filed on Apr. 7, 2005.

FIELD OF THE INVENTION

The present invention relates generally to genetic control of pestinfestations in plants and in and on animals. More specifically, thepresent invention relates to the methods for modifying endogenousexpression of coding sequences in the cell or tissue of a particularpest. More specifically, the present invention utilizes recombinant DNAtechnologies to post-transcriptionally repress or inhibit expression ofa target coding sequence in the cell of a pest, by feeding to the pestone or more double stranded or small interfering ribonucleic acid (RNA)molecules transcribed from all or a portion of a target coding sequence,thereby controlling the infestation. Therefore, the present inventionrelates to sequence-specific inhibition of expression of codingsequences using double-stranded RNA (dsRNA) or small interfering RNA(siRNA) to achieve the intended levels of pest control.

Novel isolated and substantially purified nucleic acid moleculesincluding but not limited to non-naturally occurring nucleotidesequences and recombinant DNA constructs for transcribing the dsRNA orsiRNA molecules of the present invention are also provided that suppressor inhibit the expression of an endogenous coding sequence or a targetcoding sequence in the pest when introduced thereto. Transgenic plantsthat (a) contain nucleotide sequences encoding the isolated andsubstantially purified nucleic acid molecules and the non-naturallyoccurring recombinant DNA constructs for transcribing the dsRNA or siRNAmolecules for controlling plant pest infestations, and (b) displayresistance and/or enhanced tolerance to the insect infestations, arealso provided. Compositions containing the dsRNA nucleotide sequences ofthe present invention for use in topical applications onto plants oronto animals or into the environment of an animal to achieve theelimination or reduction of pest infestation are also described.

FIELD OF THE INVENTION

The present invention relates generally to genetic control of pestinfestations in plants and in and on animals. More specifically, thepresent invention relates to the methods for modifying endogenousexpression of coding sequences in the cell or tissue of a particularpest. More specifically, the present invention utilizes recombinant DNAtechnologies to post-transcriptionally repress or inhibit expression ofa target coding sequence in the cell of a pest, by feeding to the pestone or more double stranded or small interfering ribonucleic acid (RNA)molecules transcribed from all or a portion of a target coding sequence,thereby controlling the infestation. Therefore, the present inventionrelates to sequence-specific inhibition of expression of codingsequences using double-stranded RNA (dsRNA) or small interfering RNA(siRNA) to achieve the intended levels of pest control.

Novel isolated and substantially purified nucleic acid moleculesincluding but not limited to non-naturally occurring nucleotidesequences and recombinant DNA constructs for transcribing the dsRNA orsiRNA molecules of the present invention are also provided that suppressor inhibit the expression of an endogenous coding sequence or a targetcoding sequence in the pest when introduced thereto. Transgenic plantsthat (a) contain nucleotide sequences encoding the isolated andsubstantially purified nucleic acid molecules and the non-naturallyoccurring recombinant DNA constructs for transcribing the dsRNA or siRNAmolecules for controlling plant pest infestations, and (b) displayresistance and/or enhanced tolerance to the insect infestations, arealso provided. Compositions containing the dsRNA nucleotide sequences ofthe present invention for use in topical applications onto plants oronto animals or into the environment of an animal to achieve theelimination or reduction of pest infestation are also described.

BACKGROUND OF THE INVENTION

The environment in which humans live is replete with pest infestation.Pests including insects, arachnids, crustaceans, fungi, bacteria,viruses, nematodes, flatworms, roundworms, pinworms, hookworms,tapeworms, trypanosomes, schistosomes, botflies, fleas, ticks, mites,and lice and the like are pervasive in the human environment, and amultitude of means have been utilized for attempting to controlinfestations by these pests. Compositions for controlling infestationsby microscopic pests such as bacteria, fungi, and viruses have beenprovided in the form of antibiotic compositions, antiviral compositions,and antifungal compositions. Compositions for controlling infestationsby larger pests such as nematodes, flatworm, roundworms, pinworms,heartworms, tapeworms, trypanosomes, schistosomes, and the like havetypically been in the form of chemical compositions which can either beapplied to the surfaces of substrates on which pests are known toinfest, or to be ingested by an infested animal in the form of pellets,powders, tablets, pastes, or capsules and the like. The presentinvention is directed to providing an improved means for controllingpest infestation compared to the compositions known in the art.

Commercial crops are often the targets of insect attack. Substantialprogress has been made in the last a few decades towards developing moreefficient methods and compositions for controlling insect infestationsin plants. Chemical pesticides have been very effective in eradicatingpest infestations. However, there are several disadvantages to usingchemical pesticidal agents. Chemical pesticidal agents are notselective. Applications of chemical pesticides are intended to controlinvertebrate pests that are harmful to various crops and other plants.However, because of the lack of selectivity, the chemical pesticidalagents exert their effects on non-target fauna as well, ofteneffectively sterilizing a field for a period of time over which thepesticidal agents have been applied. Chemical pesticidal agents persistin the environment and generally are slow to be metabolized, if at all.They accumulate in the food chain, and particularly in the higherpredator species. Accumulations of these chemical pesticidal agentsresults in the development of resistance to the agents and in specieshigher up the evolutionary ladder, act as mutagens and/or carcinogensoften causing irreversible and deleterious genetic modifications. Thusthere has been a long felt need for environmentally friendly methods forcontrolling or eradicating insect infestation on or in plants, i.e.,methods which are selective, environmentally inert, non-persistent, andbiodegradable, and that fit well into pest resistance managementschemes.

Compositions that include Bacillus thuringiensis (B.t.) bacteria havebeen commercially available and used as environmentally safe andacceptable insecticides for more than thirty years. The insecticidaleffect of Bt bacteria arises as a result of proteins that are producedexclusively by these bacteria that do not persist in the environment,that are highly selective as to the target species affected, exert theireffects only upon ingestion by a target pest, and have been shown to beharmless to plants and other non-targeted organisms, including humans.Transgenic plants containing one or more genes encoding insecticidalB.t. protein are also available in the art and are remarkably efficientin controlling insect pest infestation. A substantial result of the useof recombinant plants expressing Bt insecticidal proteins is a markeddecrease in the amount of chemical pesticidal agents that are applied tothe environment to control pest infestation in crop fields in areas inwhich such transgenic crops are used. The decrease in application ofchemical pesticidal agents has resulted in cleaner soils and cleanerwaters running off of the soils into the surrounding streams, rivers,ponds and lakes. In addition to these environmental benefits, there hasbeen a noticeable increase in the numbers of beneficial insects in cropfields in which transgenic insect resistant crops are grown because ofthe decrease in the use of chemical insecticidal agents.

Antisense methods and compositions have been reported in the art and arebelieved to exert their effects through the synthesis of asingle-stranded RNA molecule that in theory hybridizes in vivo to asubstantially complementary sense strand RNA molecule. Antisensetechnology has been difficult to employ in many systems for threeprinciple reasons. First, the antisense sequence expressed in thetransformed cell is unstable. Second, the instability of the antisensesequence expressed in the transformed cell concomitantly createsdifficulty in delivery of the sequence to a host, cell type, orbiological system remote from the transgenic cell. Third, thedifficulties encountered with instability and delivery of the antisensesequence create difficulties in attempting to provide a dose within therecombinant cell expressing the antisense sequence that can effectivelymodulate the level of expression of the target sense nucleotidesequence.

There have been few improvements in technologies for modulating thelevel of gene expression within a cell, tissue, or organism, and inparticular, a lack of developed technologies for delaying, repressing orotherwise reducing the expression of specific genes using recombinantDNA technology. Furthermore, as a consequence of the unpredictability ofthese approaches, no commercially viable means for modulating the levelof expression of a specific gene in a eukaryotic or prokaryotic organismis available.

Double stranded RNA mediated inhibition of specific genes in variouspests has been previously demonstrated. dsRNA mediated approaches togenetic control have been tested in the fruit fly Drosophilamelanogaster (Tabara et al., (1998) Science 282:430-431). Tabara et.al.'s method for delivery of dsRNA involved generating transgenicinsects that express double stranded RNA molecules or injecting dsRNAsolutions into the insect body or within the egg sac prior to or duringembryonic development. Research investigators have previouslydemonstrated that double stranded RNA mediated gene suppression can beachieved in nematodes either by feeding or by soaking the nematodes insolutions containing double stranded or small interfering RNA moleculesand by injection of the dsRNA molecules. Rajagopal et. al. describedfailed attempts to suppress an endogenous gene in larvae of the insectpest Spodoptera litura by feeding or by soaking neonate larvae insolutions containing dsRNA specific for the target gene, but wassuccessful in suppression after larvae were injected with dsRNA into thehemolymph of 5^(th) instar larvae using a microapplicator (J. Biol.Chem., 2002, 277:46849-46851). Similarly, Mesa et al. (US2003/0150017A1) prophetically described a preferred locus for inhibitionof the lepidopteran larvae Helicoverpa armigera using dsRNA delivered tothe larvae by ingestion of a plant transformed to produce the dsRNA. Itis believed that it would be impractical to provide dsRNA molecules inthe diet of most invertebrate pest species or to inject compositionscontaining dsRNA into the bodies of invertebrate pests. The diet methodof providing dsRNA molecules to invertebrate pests is impracticalbecause RNA molecules, even stabilized double stranded RNA molecules,are in effect highly unstable in mildly alkaline or acidic environmentssuch as those found in the digestive tracts of most invertebrate pests,and easily degraded by nucleases in the environment.

Therefore, there exists a need for improved methods of modulating geneexpression by repressing, delaying or otherwise reducing gene expressionwithin a particular invertebrate pest for the purpose of controllingpest infestation or to introduce novel phenotypic traits.

SUMMARY OF THE INVENTION

The present invention, in one embodiment, comprises a method ofinhibiting expression of a target gene in an invertebrate pest.Specifically, the present invention comprises a method of modulating orinhibiting expression of one or more target genes in an invertebratepest, in particular, in lygus bugs (Lygus hesperus Knight) and the like,that cause cessation of feeding, growth, development, reproduction andinfectivity and eventually result in the death of the insect. The methodcomprises introduction of partial or fully, stabilized double-strandedRNA (dsRNA) or its modified forms such as small interfering RNA (siRNA)sequences, into the cells or into the extracellular environment, such asthe midgut, within an invertebrate pest body wherein the dsRNA or siRNAenters the cells and inhibits expression of at least one or more targetgenes and wherein inhibition of the one or more target genes exerts adeleterious effect upon the invertebrate pest. It is specificallycontemplated that the methods and compositions of the present inventionwill be useful in limiting or eliminating invertebrate pest infestationin or on any pest host, pest symbiont, or environment preferred by apest by providing one or more compositions comprising dsRNA molecules inthe diet of the pest so long as the pest digestive system pH is withinthe range of from about 4.5 to about 9.5, from about 5 to about 9, fromabout 6 to about 8, and from about pH 7.0.

The present application discloses an exemplary sequence listing filecontaining lygus specific probe sequences, primer sequences, ampliconsequences, sequences encoding double stranded RNA sequences and Unigenenucleotide sequences as set forth in SEQ ID NO:4 through SEQ ID NO:14and SEQ ID NO:180 through SEQ ID NO:184 from lygus bugs (Lygushesperus). The sequence listing also contains cDNA or EST sequences,insect specific probe sequences, primer sequences, amplicon sequences,and sequences encoding double stranded RNA sequences from coleopteraninsects including Western corn rootworm (WCR, Diabrotica virgiferavirgifera), Southern corn rootworm (SCR, Diabrotica undecempunctata),Colorado Potato Beetle (CPB, Leptinotarsa decemlineata) and Red FlourBeetle (RFB, Tribolium castaneum), from lepidopteran insects includingEuropean Corn Borer (ECB, Ostrinia nubilalis), Black Cutworm (BCW,Agrotis ipsilon), Corn Earworm (CEW, Helicoverpa zea), Fall Army worm(FAW, Spodoptera frugiperda), Cotton Ball Weevil (BWV, Anthonomusgrandis), silkworms (Bombyx mori) and Manduca sexta and from Dipteraninsects including Drosophila melanogaster, Anopheles gambiae, and Aedesaegypti, as set forth in SEQ ID NO:155 through SEQ ID NO:179. Thesequence listing is included along with this application in computerreadable form on diskette in a 144 kilobyte file namedLygus_reglisting.txt, and in paper form consisting of 74 pages.

The present invention provides a method for suppression of geneexpression in an invertebrate pest such as a a lygus or related speciescomprises the step of providing in the diet of the pest a genesuppressive amount of at least one dsRNA molecule transcribed from anucleotide sequence as set forth in SEQ ID NO:4 through SEQ ID NO:14 andSEQ ID NO:180 through SEQ ID NO:184 in the sequence listing, at leastone segment of which is complementary to an mRNA sequence formed withinthe cells of the pest, and observing the death, inhibition, stunting, orcessation of feeding of the pest.

In another aspect of the present invention, the method comprises thestep of feeding to the pest one (or more) stabilized dsRNA molecules orits modified form such as an siRNA molecule the nucleotide sequence ofwhich is at least from about 80, 81, 82, 83, 84, 85, 86, 87, 88 89, 90,91, 92, 93, 94, 95, 96, 97, 98, 99, or about 100% identical to an RNAmolecule transcribed from a nucleotide sequence selected from the groupconsisting of SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 throughSEQ ID NO:184. Accordingly, in another aspect of the present invention,a set of isolated and purified nucleotide sequences as set forth SEQ IDNO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184 in thesequence listing is provided. Nucleotide sequences disclosed herein asset forth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 throughSEQ ID NO:184 were isolated and substantially purified from the cDNAnucleotide sequences of a lygus species (Lygus hesperus), and from mRNApools isolated from the insect pest or from cDNA nucleotide sequencesderived from such mRNA pools and assembled into the Unigene sequences.The present invention provides a stabilized dsRNA or siRNA molecule forinhibition of expression of a target gene in an invertebrate pest suchas a lygus bug insect. A stabilized dsRNA or siRNA molecule can compriseleast two coding sequences that are arranged in a sense and an antisenseorientation relative to at least one promoter, wherein the nucleotidesequence that comprises a sense strand and an antisense strand arelinked or connected by a spacer sequence of at lease from about five toabout one thousand nucleotides, wherein the sense strand and theantisense strand are different in length, and wherein each of the twocoding sequences shares at least 80% sequence identity, at least 90%, atleast 95%, at least 98%, or even 100% sequence identity, to a nucleotidesequence as set forth in one of SEQ ID NO:4 through SEQ ID NO:14 and SEQID NO:180 through SEQ ID NO:184.

The invention also provides non-naturally occurring (NNO) nucleotidesequences that may be used to target genes in the invertebrate pest fordouble stranded RNA mediated suppression in order to achieve desiredinhibition of the target genes. Any one of the nucleotide sequences asset forth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 throughSEQ ID NO:184 may be used to construct such a NNO nucleotide sequence.

The present invention also provides a recombinant DNA construct encodingthe dsRNA molecules contemplated herein for introduction into a hostcell. The recombinant DNA construct comprises a nucleotide sequence thatis transcribed into RNA by the host cell. The transcribed RNA forms atleast one dsRNA molecule, such that one strand of the dsRNA molecule iscoded by a portion of the nucleotide sequence which is at least fromabout 80% to about 100% identical to a nucleotide sequence selected fromthe group consisting of SEQ ID NO:4 through SEQ ID NO:14 and SEQ IDNO:180 through SEQ ID NO:184. The recombinant DNA construct is capableof producing dsRNA molecules in the host cell and inhibiting theexpression of the endogenous gene or the target gene or a derivativethereof or a complementary sequence thereto in the host cell, or in apest cell upon ingestion of the transformed host cell by an invertebratepest. A nucleotide sequence of the present invention is placed under thecontrol of a promoter sequence that is operable in the host cell andexpressed to produce ribonucleic acid sequences that form dsRNAmolecules within the host cell. The dsRNA molecules may be furtherprocessed either in the host cell or in an invertebrate pest to formsiRNA molecules.

The present invention also provides a recombinant DNA sequence for planttransformation constructed to contain at least one non-naturallyoccurring nucleotide sequence that can be transcribed into a singlestranded RNA molecule. The single stranded RNA molecule forms a doublestranded RNA molecule in vivo through intermolecular hybridization that,when provided in the diet of an invertebrate pest, inhibits theexpression of at least one target gene in a cell of the invertebratepest. The non-naturally occurring nucleotide sequence is operably linkedto at least one promoter sequence which functions in a transgenic plantcell to transcribe the operably linked non-naturally occurringnucleotide sequence into one or more ribonucleic acid sequences. The RNAsequences self assemble into double stranded RNA molecules and areprovided in the diet of an invertebrate pest that feeds upon thetransgenic plant. The provision of the dsRNA molecules in the diet ofthe pest achieves the desired inhibition of expression of one or moretarget genes within the pest.

The present invention also provides a recombinant host cell having inits genome at least one recombinant DNA sequence that is transcribed inthe host cell to produce at least one dsRNA molecule that functions wheningested by an invertebrate pest to inhibit the expression of a targetgene in the pest. The dsRNA molecule is coded by a portion of anucleotide sequence that exhibits at least from about 80 to about 100%identity to a nucleotide sequence as set forth in SEQ ID NO:4 throughSEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184. Exemplarynucleotide sequences for use in constructing dsRNA agents forsuppressing lygus species genes are set forth in SEQ ID NO:4 through SEQID NO:14 and SEQ ID NO:180 through SEQ ID NO:184.

The present invention also provides a recombinant DNA construct forplant transformation that consists of at least two differentnon-naturally occurring sequences which, when expressed in vivo as RNAsequences and provided in the diet of an invertebrate pest, inhibit theexpression of at least two different target genes in the cell of theinvertebrate pest. The first non-naturally occurring sequence istranscribed into RNA that forms at least one first dsRNA molecule. Oneportion of the first dsRNA molecule is encoded by a portion of the firstnon-naturally occurring sequence and exhibits at least from about 80 toabout 100% identity to at least one of the nucleotide sequences as setforth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQID NO:184, and to the nucleotide sequence of the first target gene,derivative thereof, or sequence complementary thereto. The secondnon-naturally occurring sequence is transcribed into RNA that forms asecond dsRNA molecule. One portion of the second dsRNA molecule isencoded by a portion of the second non-naturally occurring sequence andexhibits at least from about 80 to about 100% identity to a nucleotidesequence selected from the group as set forth in SEQ ID NO:4 through SEQID NO:14 and SEQ ID NO:180 through SEQ ID NO:184 and to the nucleotidesequence of the second target gene, derivative thereof, or sequencecomplementary thereto. The two non-naturally occurring sequences areplaced operably under the control of at least one promoter sequence. Thepromoter sequence functions to express the first and second dsRNAmolecules in the transgenic plant cell. The dsRNA molecules are providedin a pest inhibitory concentration in the diet of an invertebrate pestfeeding on the transgenic plant, and ingestion of plant cells by thepest achieves the desired inhibition of expression of the target genesin the pest.

The present invention also provides a transformed plant cell having inits genome at least one of the aforementioned recombinant DNA sequencesfor plant transformation. Transgenic plants are generated from thetransformed plant cell, and progeny plants, seeds, and plant products,each comprising the recombinant DNA, are produced from the transgenicplants.

The methods and compositions of the present invention may be applied toany monocot and dicot plant, depending on the invertebrate pest controldesired, or may be applied to through pharmaceutically acceptableformulations to vertebrate animals in order to provide some level ofreduction of invertebrate pest infestation. Specifically, the plants areintended to comprise without limitation alfalfa, aneth, apple, apricot,artichoke, arugula, asparagus, avocado, banana, barley, beans, beet,blackberry, blueberry, broccoli, brussel sprouts, cabbage, canola,cantaloupe, carrot, cassaya, cauliflower, celery, cherry, cilantro,citrus, clementine, coffee, corn, cotton, cucumber, Douglas fir,eggplant, endive, escarole, eucalyptus, fennel, figs, gourd, grape,grapefruit, honey dew, jicama, kiwifruit, lettuce, leeks, lemon, lime,Loblolly pine, mango, melon, mushroom, nut, oat, okra, onion, orange, anornamental plant, papaya, parsley, pea, peach, peanut, pear, pepper,persimmon, pine, pineapple, plantain, plum, pomegranate, poplar, potato,pumpkin, quince, radiata pine, radicchio, radish, raspberry, rice, rye,sorghum, Southern pine, soybean, spinach, squash, strawberry, sugarbeet,sugarcane, sunflower, sweet potato, sweetgum, tangerine, tea, tobacco,tomato, turf, a vine, watermelon, wheat, yams, and zucchini plants.

The present invention also provides a pest control agent comprising adsRNA molecule transcribed from a nucleotide sequence of the presentinvention. The nucleotide sequence shares at least from about 80 toabout 100% sequence identity to at least one of the nucleotide sequencesas set forth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180through SEQ ID NO:184. In one form, the pest control agents comprisedsRNA molecules. In another form, the pest control agents comprise siRNAmolecules. In still another form, the pest control agents compriserecombinant DNA sequences that encode mRNA molecules that form the dsRNAor siRNA molecules for introduction into plants and microbes. In yetanother form, the pest control agents are microbes that containrecombinant DNA sequences that encode the RNA molecules that form thedsRNA or siRNA molecules. The pest control agent is preferably an insector a nematode pest control agent.

It is intended that the pest control agent act to reduce or eliminateinfestation of a lygus bug, but it is also contemplated that the methodsand compositions set forth herein are capable of being utilized toderive related sequences from other pests and utilize those derivativesfor controlling infestation of the other pest(s). It is furthercontemplated that the insect pest may be selected from any genus,family, or order of insect. For lygus bugs, it is contemplated that thepest be selected from the same genus, same family, or order to which alygus belongs. Further, the present inventors contemplate that thepresent invention may be used and applied to control any species fromthe insect kingdom and from nematodes, fungal pathogens, virus, bacteriaand any other invertebrate plant pests.

The invention also provides combinations of methods and compositions forcontrolling invertebrate pest infestations. One means provides the dsRNAmethods and compositions described herein for protecting plants frominsect infestation along with one or more insecticidal agents thatexhibit features different from those exhibited by the dsRNA methods andcompositions. For example, when Bt proteins are provided in the diet ofinsect pests a mode of action for controlling the insect pest isexhibited that is dramatically different from the mode of action of themethods and compositions of the present invention. A composition, eitherformulated for topical application or one derived using a transgenicapproach that combines dsRNA methods and compositions with Bt methodsand compositions results in synergies that were not known previously inthe art for controlling insect infestation. Transgenic plants thatproduce one or more dsRNA or siRNA molecules that inhibit some essentialbiological function in a target pest along with one or more B.t.insecticidal proteins that are toxic to the target pest providesurprising synergies. One synergy is the reduction in the level ofexpression required for either the dsRNA(s) or the Bt protein(s). Whencombined together, a lower effective dose of each pest control agent isrequired. It is believed that the Bt insecticidal proteins create entrypores through which the dsRNA or siRNA molecules are able to penetratemore effectively into spaces remote from the gut of the insect pest, ormore efficiently into the cells in the proximity of lesions created bythe Bt proteins, thus requiring less of either the Bt or the dsRNA toachieve the desired insecticidal result or the desired inhibition orsuppression of a targeted biological function in the target pest.

The inventors herein describe a plurality of inventions, including amethod for controlling invertebrate pest infestations by providing adiet to an invertebrate pest an agent comprising or consisting of aribonucleic acid that functions upon ingestion by the pest to inhibitthe expression of a target nucleotide sequence that is within the cellsof the pest. The ribonucleic acid that is provided in the diet consistsof a ribonucleotide sequence that is, or that is complementary to, thetarget nucleotide sequence. The ribonucleotide sequence is transcribedfrom a contiguous DNA sequence that is at least from about 19 to about5000 nucleotides in length and that is selected from the groupconsisting of the sequences disclosed herein and the complement thereof.The method provides for the construction of a nucleotide sequence thatcan be used to express an RNA molecule that can be ingested by the pestin a diet provided to the pest. The diet can be an artificial dietformulated to meet the particular nutritional requirements formaintaining a pest on such diet, and be supplemented with a pestcontrolling amount of the RNA that has been purified from a separateexpression system, the supplementation of the diet being for the purposeof determining the pest controlling amount of the RNA composition, ordeterming whether one or more particular RNA's constructed specificallyto bind or hybridize in part to one or more target sequences within thepest are functional in achieving some gene suppressive activity uponingestion of the supplemented diet by the pest. The diet can also be arecombinant cell transformed with a DNA sequence constructed forexpression of the agent, the RNA, or the gene suppression agent. Uponingestion of one or more such transformed cells by the pest, a desiredgenotypic or phenotypic result is observed, indicating that the agenthas functioned to inhibit the expression of a target nucleotide sequencethat is within the cells of the pest.

The invertebrate pest is preferably an insect, an arachnid, a nematode,a platyhelminthe, an aschelminthe, a fungal pest, or any otherinvertebrate pest for which the gene suppression technology is amenable.More preferably, the invertebrate pest is one that is particularlyproblematic in terms of infestation of animals or plants. Moreparticularly, the invertebrate pest is an insect or a nematode or afungal pest that preferentially infests crop plants, ornamentals, and/orgrasses.

A DNA sequence that is selected for use in expression of a genesuppression agent of the present invention is preferably at least fromabout 19 to about 5000 nucleotides in length, and is at least in partsubstantially identical in sequence to the sense or the antisense strandof a target sequence present in the DNA of one or more particular targetpest species. The phrase “at least in part” is intended to refer to theconcept that the DNA sequence selected for use in expression of a genesuppression agent can be constructed from a single sequence derived fromone or more target pests and intended for use in expression of an RNAthat functions in the suppression of a single gene or gene family in theone or more target pests, or that the DNA sequence can be constructed asa chimera from a plurality of DNA sequences. The plurality of DNAsequences can be each be derived from one or more nucleotide sequencesfrom within a single pest, or can be derived one or more nucleotidesequences from a plurality of different pests. In particular theselected sequence should exhibit from about 80 to about 100% nucleotidesequence identity to a nucleotide sequence from the DNA of the pestspecies. The DNA of the pest species can be identified by directlyisolating the DNA from the pest species or by identification of RNAsequences within the pest species and reverse translating the RNAsequences to DNA. Sequences exemplifying DNA from corn rootworm pestspecies are set forth herein in the sequence listing, and thecomplements thereof.

The DNA sequences selected for use in expression of a gene suppressiveRNA molecule can be included in a polynucleotide composition for use ina plant cell. In particular the DNA sequences can be incorporated into avector for use in transforming the genome of a plant cell, and can beincorporated into an expression cassette containing at least a plantfunctional promoter operably linked to the selected DNA sequence alongwith any other expression control elements desired to achieve anappropriate cellular temporal or plant spatial level of expression. Theintroduction of the polynucleotide composition into the genome of aplant cell provides a transformed cell that can be selected, providingthat appropriate selective means have been included along with thepolynucleotide composition, and regenerated into a transgenicrecombinant plant. The transgenic plant, an event, can be provided inthe diet of the pest or pests to achieve control of a pest infestation.The transgenic plant can give rise to progeny plants, plant cells, andseeds each containing the polynucleotide composition.

The present invention provides a method for protecting a platn frominsect infestation by providing to the insec pest one or more of theplants' cells each expressing a gene suppressive RNA molecule from a DNAsequence that is selected from the group consisting of the sequencesexemplified herein. The ingestion of the plant cells containing the genesuppressive RNA, the pest or insect control agent, results in theinhibition of one or more biological functions in the pest or insect.

The present invention provides a composition that contains two or moredifferent pesticidal agents each toxic to the same pest or insectspecies. As indicated herein, one of these pesticidal agents can be aRNA molecule that functions to suppress an essential biological functionin one or more cells of the pest. A second pesticidal agent can beincluded along with the first. The second agent can be a second genesuppressive RNA that is different from the first, or the second agentcan be an agent selected from the group of insecticidal proteins activein control of the invertebrate pest when provided in its diet.

The gene targeted for suppression, or the function in a pest cell or asa physiological or metatabooic aspect of the pest that is enabled by theexpression of the gene targeted for suppression, can encode an essentialprotein, the predicted function of which is selected from the groupconsisting of muscle formation, juvenile hormone formation, juvenilehormone regulation, ion regulation and transport, digestive enzymesynthesis, maintenance of cell membrane potential, amino acidbiosynthesis, amino acid degradation, sperm formation, pheromonesynthesis, pheromone sensing, antennae formation, wing formation, legformation, development and differentiation, egg formation, larvalmaturation, digestive enzyme formation, haemolymph synthesis, haemolymphmaintenance, neurotransmission, cell division, energy metabolism,respiration, and apoptosis. It is preferred that the DNA sequenceselected for constructing the suppression construct be derived from thenucleotide sequences set forth in the sequence listing for suppressionof a corn rootworm gene. It is envisioned that the method forcontrolling invertebrate pest infestation will include providing in thediet of the invertebrate pest an agent, for example, a firstribonucleotide sequence expressed from a first DNA sequence thatfunctions upon ingestion by the pest to inhibit a biological functionwithin said pest, and that the first DNA sequence exhibits from about 85to about 100% nucleotide sequence identity to a coding sequence derivedform said pest. The first ribonucleotide sequence may be hybridized to asecond ribonucleotide sequence that is complimentary or substantiallycomplimentary to the first ribonucleotide sequence, and the secondribonucleotide sequence is expressed from a second DNA sequence thatcorresponds to a coding sequence derived from the invertebrate pest,selected from the sequences set forth herein in the sequence listing, orthe complements thereof. It is preferred that the first and the secondDNA sequence comprise a contiguous sequence of identity to one or moreof the sequences set forth in the sequence listing, and be from about 14to about 25 or more contiguous nucleotides.

The invention functions at optimum when a diet containing a pest genesuppressive amount of an insecticidal agent, such as one or more RNAmolecules produced from the expression of one or more sequences setforth herein in the sequence listing, are provided to an invertebratepest that exhibits a digestive system pH that is from about 4.5 to about9.5, or from about 5.0 to about 9.0, or from about 5.5 to about 8.5, orfrom about 6.0 to about 8.0, or from about 6.5 to about 7.0, or about7.0. Any of the methods, nucleic acids, ribonucleic acids,ribonucleotide sequences, compositions, plants, plant cells, progenyplants, seeds, insect control agents, pest control agents, expressioncassettes, described herein are optionally functional when provided in adiet to one or more pests that comprise such a digestive tract pH.

The diet of the present invention can be any pest sufficient dietincluding but not limited to an artificial diet or formulation, a plantcell, a plurality of plant cells, a plant tissue, a plant root, a plantseed, and a plant grown from a plant seed, wherein the diet comprises apest inhibitory amount of an RNA molecule encoded from a DNA sequencethat is or is complimentary to, or is substantially or is substantiallycomplimentary to one or more contiguous at least from about 19 to about5000 nucleotides selected from the nucleotide sequences set forth in thesequence listing, or selected from nucleotide sequences derived from aparticular invertebrate pest species.

Agronomically and commercially important products and/or compositions ofmatter including but not limited to animal feed, commodities, and cornproducts and by-products that are intended for use as food for humanconsumption or for use in compositions and commodities that are intendedfor human consumption including but not limited to corn flour, cornmeal, corn syrup, corn oil, corn starch, popcorn, corn cakes, cerealscontaining corn and corn by-products, and the like are intended to bewithin the scope of the present invention if these products andcompositions of matter contain detectable amounts of the nucleotidesequences set forth herein as being diagnostic for any transgenic eventcontaining such nucleotide sequences. These products are useful at leastbecause they are likely to be derived from crops and produce that arepropagated in fields containing fewer pestidides and organophosphates asa result of their incorporation of the nucleotides of the presentinvention for controlling the infestation of invertebrate pests inplants. Such commodities and commodity products are produced from seedproduced from a transgenic plant, wherein the transgenic plant expressesRNA from one or more contiguous nucleotides of the present invention ornucleotides of one or more invertebrate pests and the complimentsthereof. Such commodities and commodity products may also be useful incontrolling invertebrate pests of such commodity and commodity products,such as for example, control of flour weevils, because of the presencein the commodity or commodity product of the pest gene suppressive RNAexpressed from a gene sequence as set forth in the present invention.

The invention also provides a computer readable medium having recordedthereon one or more of the nucleotide sequences as set forth in SEQ IDNO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184 orcomplements thereof, for use in a number of computer based applications,including but not limited to DNA identity and similarity searching,protein identity and similarity searching, transcription profilingcharacterizations, comparisons between genomes, and artificialhybridization analyses.

DETAILED DESCRIPTION OF THE INVENTION

The following is a detailed description of the invention provided to aidthose skilled in the art in practicing the present invention.Modifications and variations in the embodiments described herein may bemade by those of ordinary skill in the art without departing from thespirit or scope of the present invention.

The inventors have herein discovered that, contrary to the teachings inthe prior art, feeding a composition containing double stranded RNAmolecules consisting of sequences found within one or more expressednucleotide sequences of an invertebrate species to the invertebratespecies from which the nucleotide sequences were obtained results in theinhibition of one or more biological functions within the invertebratespecies. Particularly, the inventors have discovered that feeding doublestranded RNA molecules consisting of lygus bug RNA sequencesrespectively to lygus bugs can result in the death or inhibition ofdevelopment and differentiation of the lygus bugs that ingest thesecompositions.

The inventors have identified the nucleotide sequence of thousands ofcDNA sequences obtained from each of the invertebrate pest species.Amino acid sequences encoded by the cDNA sequences were deduced andcompared to all known amino acid sequences. Many of the cDNA sequencesare predicted to encode proteins that have some annotation informationassociated with them. The annotation information that is associated witha particular nucleotide sequence and protein sequence encoded therefromis based on homology or similarity between the amino acid sequencesdeduced through translation of the cDNA sequences described herein andamino acid sequences that are known in the art in publicly availabledatabases. The deduced amino acid sequences as set forth herein wereBLASTX-ed against all known amino acid sequences, and likelyfunctionalities of each of the deduced amino acid sequences wereassigned based on the alignment results. cDNA sequences encodingproteins or parts of proteins known in the art to be essential forsurvival, such as amino acid sequences involved in various metabolic orcatabolic biochemical pathways, cell division, reproduction, energymetabolism, digestion, neurological function and the like were selectedfor use in preparing double stranded RNA molecules that were provided inthe diet of an invertebrate pest. As described herein, ingestion by atarget pest of compositions containing one or more dsRNA's, at least onesegment of which corresponds to at least a substantially identicalsegment of RNA produced in the cells of the target pest, resulted indeath, stunting, or other inhibition of the target pest. These resultsindicated that a nucleotide sequence, either DNA or RNA, derived from aninvertebrate pest can be used to construct a recombinant pest host orsymbiont that is a target for infestation by the pest. The pest host orsymbiont can be transformed to contain one or more of the nucleotidesequences derived from the invertebrate pest. The nucleotide sequencetransformed into the pest host or symbiont encodes one or more RNA'sthat form into a dsRNA sequence in the cells or biological fluids withinthe transformed host or symbiont, thus making the dsRNA available in thediet of the pest if/when the pest feeds upon the transgenic host orsymbiont, resulting in the suppression of expression of one or moregenes in the cells of the pest and ultimately the death, stunting, orother inhibition of the pest.

The present invention relates generally to genetic control ofinvertebrate pest infestations in host organisms. More particularly, thepresent invention includes the methods for delivery of pest controlagents to an invertebrate pest. Such pest control agents cause, directlyor indirectly, an impairment in the ability of the pest to maintainitself, grow or otherwise infest a target host or symbiont. The presentinvention provides methods for employing stabilized dsRNA molecules inthe diet of the pest as a means for suppression of targeted genes in thepest, thus achieving desired control of pest infestations in, or aboutthe host or symbiont targeted by the pest. Transgenic plants can beproduced using the methods of the present invention that expressrecombinant stabilized dsRNA or siRNA molecules.

In accomplishing the foregoing, the present invention provides a methodof inhibiting expression of a target gene in an invertebrate pest, andin particular, in lygus bugs or other piercing and sucking insects,resulting in the cessation of feeding, growth, development,reproduction, infectivity, and eventually may result in the death of thepest. The method comprises introducing partial or fully, stabilizeddouble-stranded RNA (dsRNA) nucleotide molecules or their modified formssuch as small interfering RNA (siRNA) molecules into a nutritionalcomposition that the pest relies on as a food source, and making thenutritional composition available to the pest for feeding. Ingestion ofthe nutritional composition containing the double stranded or siRNAmolecules results in the uptake of the molecules by the cells of thepest, resulting in the inhibition of expression of at least one targetgene in the cells of the pest. Inhibition of the target gene exerts adeleterious effect upon the pest. dsRNA molecules or siRNA moleculesconsist of nucleotide sequences as set forth in any of SEQ ID NO:4through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184, theinhibition of which results in the reduction or removal of a protein ornucleotide sequence agent that is essential for the pests' growth anddevelopment or other biological function. The nucleotide sequenceselected exhibits from about 80% to about 100% sequence identity to oneof the nucleotide sequences as set forth in SEQ ID NO:4 through SEQ IDNO:14 and SEQ ID NO:180 through SEQ ID NO:184, or the complementthereof. Such inhibition is specific in that a nucleotide sequence froma portion of the target gene is chosen from which the inhibitory dsRNAor siRNA is transcribed. The method is effective in inhibiting theexpression of at least one target gene and can be used to inhibit manydifferent types of target genes in the pest.

The present invention also provides different forms of the pest controlagents to achieve the desired reduction in pest infestation. In oneform, the pest control agents comprise dsRNA molecules. In another form,the pest control agents comprise siRNA molecules. In still another form,the pest control agents comprise recombinant DNA constructs that can beused to stably transform microorganisms or plants, enabling thetransformed microbes or plants to encode the dsRNA or siRNA molecules.In another form, the pest control agents are microbes that contain therecombinant DNA constructs encoding the dsRNA or siRNA molecules.

Pairs of isolated and purified nucleotide sequences are provided fromcDNA library and/or genomic library information. The pairs of nucleotidesequences are derived from any preferred invertebrate pest for use asthermal amplification primers to generate the dsRNA and siRNA moleculesof the present invention.

The present invention provides recombinant DNA constructs for use inachieving stable transformation of particular host or symbiont pesttargets. Transformed host or symbiont pest targets express pesticidallyeffective levels of preferred dsRNA or siRNA molecules from therecombinant DNA constructs, and provide the molecules in the diet of thepest.

The present invention also provides, as an example of a transformed hostor symbiont pest target organism, transformed plant cells andtransformed plants and their progeny. The transformed plant cells andtransformed plants express one or more of the dsRNA or siRNA sequencesof the present invention from one or more of the DNA sequences as setforth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQID NO:184, or the complement thereof.

As used herein the words “gene suppression”, when taken together, areintended to refer to any of the well-known methods for reducing thelevels of protein produced as a result of gene transcription to mRNA andsubsequent translation of the mRNA. Gene suppression is also intended tomean the reduction of protein expression from a gene or a codingsequence including posttranscriptional gene suppression andtranscriptional suppression. Posttranscriptional gene suppression ismediated by the homology between of all or a part of a mRNA transcribedfrom a gene or coding sequence targeted for suppression and thecorresponding double stranded RNA used for suppression, and refers tothe substantial and measurable reduction of the amount of available mRNAavailable in the cell for binding by ribosomes. The transcribed RNA canbe in the sense orientation to effect what is called co-suppression, inthe anti-sense orientation to effect what is called anti-sensesuppression, or in both orientations producing a dsRNA to effect what iscalled RNA interference (RNAi). Transcriptional suppression is mediatedby the presence in the cell of a dsRNA, a gene suppression agent,exhibiting substantial sequence identity to a promoter DNA sequence orthe complement thereof to effect what is referred to as promoter transsuppression. Gene suppression may be effective against a native plantgene associated with a trait, e.g., to provide plants with reducedlevels of a protein encoded by the native gene or with enhanced orreduced levels of an affected metabolite. Gene suppression can also beeffective against target genes in plant pests that may ingest or contactplant material containing gene suppression agents, specifically designedto inhibit or suppress the expression of one or more homologous orcomplementary sequences in the cells of the pest.

Post-transcriptional gene suppression by anti-sense or sense orientedRNA to regulate gene expression in plant cells is disclosed in U.S. Pat.Nos. 5,107,065, 5,759,829, 5,283,184, and 5,231,020. The use of dsRNA tosuppress genes in plants is disclosed in WO 99/53050, WO 99/49029, U.S.Patent Application Publication No. 2003/0175965 A1, and 2003/0061626 A1,U.S. patent applications No. 10/465,800, and U.S. Pat. Nos. 6,506,559,and 6,326,193.

A preferred method of post transcriptional gene suppression in plantsemploys both sense-oriented and anti-sense-oriented, transcribed RNAwhich is stabilized, e.g., as a hairpin and stem and loop structure. Apreferred DNA construct for effecting post transcriptional genesuppression one in which a first segment encodes an RNA exhibiting ananti-sense orientation exhibiting substantial identity to a segment of agene targeted for suppression, which is linked to a second segmentencoding an RNA exhibiting substantial complementarity to the firstsegment. Such a construct would be expected to form a stem and loopstructure by hybridization of the first segment with the second segmentand a loop structure from the nucleotide sequences linking the twosegments (see WO94/01550, WO98/05770, U.S. 2002/0048814A1, and U.S.2003/0018993A1).

As used herein, the term “nucleic acid” refers to a single ordouble-stranded polymer of deoxyribonucleotide or ribonucleotide basesread from the 5′ to the 3′ end. The “nucleic acid” may also optionallycontain non-naturally occurring or altered nucleotide bases that permitcorrect read through by a polymerase and do not reduce expression of apolypeptide encoded by that nucleic acid. The term “nucleotide sequence”or “nucleic acid sequence” refers to both the sense and antisensestrands of a nucleic acid as either individual single strands or in theduplex. The term “ribonucleic acid” (RNA) is inclusive of RNAi(inhibitory RNA), dsRNA (double stranded RNA), siRNA (small interferingRNA), mRNA (messenger RNA), mRNA (micro-RNA), tRNA (transfer RNA,whether charged or discharged with a corresponding acylated amino acid),and cRNA (complementary RNA) and the term “deoxyribonucleic acid” (DNA)is inclusive of cDNA and genomic DNA and DNA-RNA hybrids. The words“nucleic acid segment”, “nucleotide sequence segment”, or more generally“segment” will be understood by those in the art as a functional termthat includes both genomic sequences, ribosomal RNA sequences, transferRNA sequences, messenger RNA sequences, operon sequences and smallerengineered nucleotide sequences that express or may be adapted toexpress, proteins, polypeptides or peptides.

As used herein, the term “pest” refers to insects, arachnids,crustaceans, fungi, bacteria, viruses, nematodes, flatworms, roundworms,pinworms, hookworms, tapeworms, trypanosomes, schistosomes, botflies,fleas, ticks, mites, and lice and the like that are pervasive in thehuman environment and that may ingest or contact one or more cells,tissues, or fluids produced by a pest host or symbiont transformed toexpress or coated with a double stranded gene suppression agent or thatmay ingest plant material containing the gene suppression agent. As usedherein, a “pest resistance” trait is a characteristic of a transgenicplant, transgenic animal, transgenic host or transgenic symbiont thatcauses the plant, animal, host, or symbiont to be resistant to attackfrom a pest that typically is capable of inflicting damage or loss tothe plant, animal, host or symbiont. Such pest resistance can arise froma natural mutation or more typically from incorporation of recombinantDNA that confers pest resistance. To impart insect resistance to atransgenic plant a recombinant DNA can, for example, encode an insectlethal or insect inhibitory protein such as a delta endotoxin derivedfrom a B. thuringiensis bacterium, e.g. as is used in commerciallyavailable varieties of cotton and corn, or be transcribed into a RNAmolecule that forms a dsRNA molecule within the tissues or fluids of therecombinant plant. The dsRNA molecule is comprised in part of a segmentof RNA that is identical to a corresponding RNA segment encoded from aDNA sequence within an insect pest that prefers to feed on therecombinant plant. Expression of the gene within the target insect pestis suppressed by the dsRNA, and the suppression of expression of thegene in the target insect pest results in the plant being insectresistant. Fire et al. (U.S. Pat. No. 6,506,599) generically describedinhibition of pest infestation, providing specifics only about severalnucleotide sequences that were effective for inhibition of gene functionin the nematode species Caenorhabditis elegans. Similarly, Plaetinck etal. (US 2003/0061626A1) describe the use of dsRNA for inhibiting genefunction in a variety of nematode pests. Mesa et al. (US 2003/0150017A1) describe using dsDNA sequences to transform host cells to expresscorresponding dsRNA sequences that are substantially identical to targetsequences in specific pathogens, and particularly describe constructingrecombinant plants expressing such dsRNA sequences for ingestion byvarious plant pests, facilitating down-regulation of a gene in thegenome of the pest and improving the resistance of the plant to the pestinfestation.

The present invention provides for inhibiting gene expression of one ormultiple target genes in a target insect using stabilized dsRNA methods.The invention is particularly useful in the modulation of eukaryoticgene expression, in particular the modulation of expression of genespresent in insects that exhibit a digestive system pH level that is fromabout 4.5 to about 9.5, more preferably from about 5.0 to about 8.0, andeven more preferably from about 6.5 to about 7.5. Plant pests with adigestive system that exhibits pH levels outside of these ranges are notpreferred candidates for double stranded RNA mediated methods for genesuppression using a delivery method that requires ingestion of thepreferred dsRNA molecules. The modulatory effect is applicable to avariety of genes expressed in the pests including, for example,endogenous genes responsible for cellular metabolism or cellulartransformation, including house keeping genes, transcription factors andother genes which encode polypeptides involved in cellular metabolism.

As used herein, the term “expression” refers to the transcription andstable accumulation of sense or antisense RNA derived from the nucleicacids disclosed in the present invention. Expression may also refer totranslation of mRNA into a polypeptide or protein. As used herein, theterm “sense” RNA refers to an RNA transcript corresponding to a sequenceor segment that, when produced by the target pest, is in the form of amRNA that is capable of being translated into protein by the target pestcell. As used herein, the term “antisense RNA” refers to an RNAtranscript that is complementary to all or a part of a mRNA that isnormally produced in a cell of a target pest. The complementarity of anantisense RNA may be with any part of the specific gene transcript,i.e., at the 5′ non-coding sequence, 3′ non-translated sequence,introns, or the coding sequence. As used herein, the term “RNAtranscript” refers to the product resulting from RNApolymerase-catalyzed transcription of a DNA sequence. When the RNAtranscript is a perfect complementary copy of the DNA sequence, it isreferred to as the primary transcript or it may be an RNA sequencederived from post-transcriptional processing of the primary transcriptand is referred to as the mature RNA.

As used herein, the phrase “inhibition of gene expression” or“inhibiting expression of a target gene in the cell of an insect” refersto the absence (or observable decrease) in the level of protein and/ormRNA product from the target gene. Specificity refers to the ability toinhibit the target gene without manifest effects on other genes of thecell and without any effects on any gene within the cell that isproducing the dsRNA molecule. The inhibition of gene expression of thetarget gene in the insect pest may result in novel phenotypic traits inthe insect pest.

Without limiting the scope of the present invention, there is provided,in one aspect, a method for controlling infestation of a target insectusing the stabilized dsRNA strategies. The method involves generatingstabilized dsRNA molecules as one type of the insect control agents toinduce gene silencing in an insect pest. The insect control agents ofthe present invention induce directly or indirectly post-transcriptionalgene silencing events of target genes in the insect. Down-regulation ofexpression of the target gene prevents or at least retards the insect'sgrowth, development, reproduction and infectivity to hosts. As usedherein, the phrase “generating stabilized dsRNA molecule” refers to themethods of employing recombinant DNA technologies readily available inthe art (e.g., by Sambrook, et al., 1989) to construct a DNA nucleotidesequence that transcript the stabilized dsRNA. The detailed constructionmethods of the present invention are disclosed below in this disclosure.As used herein, the term “silencing” refers the effective“down-regulation” of expression of the targeted nucleotide sequence and,hence, the elimination of the ability of the sequence to cause an effectwithin the insect's cell.

The present invention provides in part a delivery system for thedelivery of the insect control agents to insects through their exposureto a diet containing the insect control agents of the present invention.In accordance with one of the embodiments, the stabilized dsRNA or siRNAmolecules may be incorporated in the insect diet or may be overlaid onthe top of the diet for consumption by an insect.

The present invention also provides in part a delivery system for thedelivery of the insect control agents to insects through their exposureto an microorganism or a host such as a plant containing the insectcontrol agents of the present invention by ingestion of themicroorganism or the host cells or the contents of the cells. Inaccordance with another one of the embodiments, the present inventioninvolves generating a transgenic plant cell or a plant that contains arecombinant DNA construct transcribing the stabilized dsRNA molecules ofthe present invention. As used herein, the phrase “generating atransgenic plant cell or a plant” refers to the methods of employing therecombinant DNA technologies readily available in the art (e.g., bySambrook, et al., 1989) to construct a plant transformation vectortranscribing the stabilized dsRNA molecules of the present invention, totransform the plant cell or the plant and to generate the transgenicplant cell or the transgenic plant that contain the transcribed,stabilized dsRNA molecules. In particular, the method of the presentinvention may comprise the recombinant construct in a cell of a plantthat results in dsRNA transcripts that are substantially homologous toan RNA sequence encoded by a nucleotide sequence within the genome of aninsect. Where the nucleotide sequence within the genome of an insectencodes a gene essential to the viability and infectivity of the insect,its down-regulation results in a reduced capability of the insect tosurvive and infect host cells. Hence, such down-regulation results in a“deleterious effect” on the maintenance viability and infectivity of theinsect, in that it prevents or reduces the insect's ability to feed offand survive on nutrients derived from the host cells. By virtue of thisreduction in the insect's viability and infectivity, resistance and/orenhanced tolerance to infection by an insect is facilitated in the cellsof a plant. Genes in the insect may be targeted at the mature (adult),immature (larval), or egg stages.

In still another embodiment, non-pathogenic, attenuated strains ofmicroorganisms may be used as a carrier for the insect control agentsand, in this perspective, the microorganisms carrying such agents arealso referred to as insect control agents. The microorganisms may beengineered to express a nucleotide sequence of a target gene to produceRNA molecules comprising RNA sequences homologous or complementary toRNA sequences typically found within the cells of an insect. Exposure ofthe insects to the microorganisms result in ingestion of themicroorganisms and down-regulation of expression of target genesmediated directly or indirectly by the RNA molecules or fragments orderivatives thereof.

The present invention alternatively provides exposure of an insect tothe insect control agents of the present invention incorporated in aspray mixer and applied to the surface of a host, such as a host plant.In an exemplary embodiment, ingestion of the insect control agents by aninsect delivers the insect control agents to the gut of the insect andsubsequently to the cells within the body of the insect. In anotherembodiment, infection of the insect by the insect control agents throughother means such as by injection or other physical methods also permitsdelivery of the insect control agents. In yet another embodiment, theRNA molecules themselves are encapsulated in a synthetic matrix such asa polymer and applied to the surface of a host such as a plant.Ingestion of the host cells by an insect permits delivery of the insectcontrol agents to the insect and results in down-regulation of a targetgene in the host.

It is envisioned that the compositions of the present invention can beincorporated within the seeds of a plant species either as a product ofexpression from a recombinant gene incorporated into a genome of theplant cells, or incorporated into a coating or seed treatment that isapplied to the seed before planting. The plant cell containing arecombinant gene is considered herein to be a transgenic event.

It is believed that a pesticidal seed treatment can provide significantadvantages when combined with a transgenic event that providesprotection from invertebrate pest infestation that is within thepreferred effectiveness range against a target pest. In addition, it isbelieved that there are situations that are well known to those havingskill in the art, where it is advantageous to have such transgenicevents within the preferred range of effectiveness.

The present invention also includes seeds and plants having more thatone transgenic event. Such combinations are referred to as “stacked”transgenic events. These stacked transgenic events can be events thatare directed at the same target pest, or they can be directed atdifferent target pests. In one preferred method, a seed having theability to express a Cry3 protein or insecticidal variant thereof alsohas the ability to express at least one other insecticidal agentincluding but not limited to a protein that is different from a Cry3protein and/or an RNA molecule the sequence of which is derived from thesequence of an RNA expressed in a target pest and that forms a doublestranded RNA structure upon expressing in the seed or cells of a plantgrown from the seed, wherein the ingestion of one or more cells of theplant by the target pest results in the suppression of expression of theRNA in the cells of the target pest.

In another preferred method, the seed having the ability to express adsRNA the sequence of which is derived from a target pest also has atransgenic event that provides herbicide tolerance. It is preferred thatthe transgenic event that provides herbicide tolerance is an event thatprovides resistance to glyphosate, N-(phosphonomethyl) glycine,including the isopropylamine salt form of such herbicide.

In the present method, a seed comprising a transgenic event is treatedwith a pesticide. It is believed that the combination of a transgenicseed exhibiting bioactivity against a target pest as a result of theproduction of an insecticidal amount of an insecticidal dsRNA within thecells of the transgenic seed or plant grown from the seed coupled withtreatment of the seed with certain chemical or protein pesticidesprovides unexpected synergistic advantages to seeds having suchtreatment, including unexpectedly superior efficacy for protectionagainst damage to the resulting transgenic plant by the target pest. Inparticular, it is believed that the treatment of a transgenic seed thatis capable of expressing certain constructs that form dsRNA molecules,the sequence of which are derived from one or more sequences expressedin a lygus, with from about 100 gm to about 400 gm of certain pesticidesper 100 kg of seed provided unexpectedly superior protection againstlygus. In addition, it is believed that such combinations are alsoeffective to protect the emergent corn plants against damage by blackcutworm. The seeds of the present invention are also believed to havethe property of decreasing the cost of pesticide use, because less ofthe pesticide can be used to obtain a required amount of protection thanif the innovative composition and method is not used. Moreover, becauseless pesticide is used and because it is applied prior to planting andwithout a separate field application, it is believed that the subjectmethod is therefore safer to the operator and to the environment, and ispotentially less expensive than conventional methods.

When it is said that some effects are “synergistic”, it is meant toinclude the synergistic effects of the combination on the pesticidalactivity (or efficacy) of the combination of the transgenic event andthe pesticide. However, it is not intended that such synergistic effectsbe limited to the pesticidal activity, but that they should also includesuch unexpected advantages as increased scope of activity, advantageousactivity profile as related to type and amount of damage reduction,decreased cost of pesticide and application, decreased pesticidedistribution in the environment, decreased pesticide exposure ofpersonnel who produce, handle and plant corn seeds, and other advantagesknown to those skilled in the art.

Pesticides and insecticides that are useful in compositions incombination with the methods and compositions of the present invention,including as seed treatments and coatings as well as methods for usingsuch compositions can be found, for example, in U.S. Pat. No. 6,551,962,the entirety of which is incorporated herein by reference.

It has been found that the present invention is useful to protect seedsand plants against a wide array of agricultural pests, includinginsects, mites, fungi, yeasts, molds, bacteria, nematodes, weeds, andparasitic and saprophytic plants.

It is preferred that the seed treatments and coatings described hereinbe used along with transgenic seeds of the present invention, inparticular by application of a pesticidal agent other than the dsRNAmolecules derived from the sequences described herein as set forth inSEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184or the complements thereof to a transgenic seed. Although it is believedthat the seed treatments can be applied to a transgenic seed in anyphysiological state, it is preferred that the seed be in a sufficientlydurable state that it incurs no damage during the treatment process.Typically, the seed would be a seed that had been harvested from thefield; removed from the transgenic plant; and separated from any othernon-seed plant material. The seed would preferably also be biologicallystable to the extent that the treatment would cause no biological damageto the seed. In one embodiment, for example, the treatment can beapplied to seed corn that has been harvested, cleaned and dried to amoisture content below about 15% by weight. In an alternativeembodiment, the seed can be one that has been dried and then primed withwater and/or another material and then re-dried before or during thetreatment with the pesticide. Within the limitations just described, itis believed that the treatment can be applied to the seed at any timebetween harvest of the seed and sowing of the seed. As used herein, theterm “unsown seed” is meant to include seed at any period between theharvest of the seed and the sowing of the seed in the ground for thepurpose of germination and growth of the plant.

When it is said that unsown seed is “treated” with the pesticide, suchtreatment is not meant to include those practices in which the pesticideis applied to the soil, rather than to the seed. For example, suchtreatments as the application of the pesticide in bands, “T”-bands, orin-furrow, at the same time as the seed is sowed are not considered tobe included in the present invention.

The pesticide, or combination of pesticides, can be applied “neat”, thatis, without any diluting or additional components present. However, thepesticide is typically applied to the seeds in the form of a pesticideformulation. This formulation may contain one or more other desirablecomponents including but not limited to liquid diluents, binders toserve as a matrix for the pesticide, fillers for protecting the seedsduring stress conditions, and plasticizers to improve flexibility,adhesion and/or spreadability of the coating. In addition, for oilypesticide formulations containing little or no filler, it may bedesirable to add to the formulation drying agents such as calciumcarbonate, kaolin or bentonite clay, perlite, diatomaceous earth or anyother adsorbent material. Use of such components in seed treatments isknown in the art. See, e.g., U.S. Pat. No. 5,876,739. The skilledartisan can readily select desirable components to use in the pesticideformulation depending on the seed type to be treated and the particularpesticide that is selected.

The subject pesticides can be applied to a seed as a component of a seedcoating. Seed coating methods and compositions that are known in the artare useful when they are modified by the addition of one of theembodiments of the combination of pesticides of the present invention.Such coating methods and apparatus for their application are disclosedin, for example, U.S. Pat. Nos. 5,918,413, 5,891,246, 5,554,445,5,389,399, 5,107,787, 5,080,925, 4,759,945 and 4,465,017. Seed coatingcompositions are disclosed, for example, in U.S. Pat. Nos. 5,939,356,5,882,713, 5,876,739, 5,849,320, 5,834,447, 5,791,084, 5,661,103,5,622,003, 5,580,544, 5,328,942, 5,300,127, 4,735,015, 4,634,587,4,383,391, 4,372,080, 4,339,456, 4,272,417 and 4,245,432, among others.

The pesticides that are useful in the coating are those pesticides thatare described herein. The amount of pesticide that is used for thetreatment of the seed will vary depending upon the type of seed and thetype of active ingredients, but the treatment will comprise contactingthe seeds with an amount of the combination of pesticides that ispesticidally effective. When insects are the target pest, that amountwill be an amount of the insecticide that is insecticidally effective.As used herein, an insecticidally effective amount means that amount ofinsecticide that will kill insect pests in the larvae or pupal state ofgrowth, or will consistently reduce or retard the amount of damageproduced by insect pests.

In general, the amount of pesticide that is applied to the seed in thetreatment will range from about 10 gm to about 2000 gm of the activeingredient of the pesticide per 100 kg of the weight of the seed.Preferably, the amount of pesticide will be within the range of about 50gm to about 1000 gm active per 100 kg of seed, more preferably withinthe range of about 100 gm to about 600 gm active per 100 kg of seed, andeven more preferably within the range of about 200 gm to about 500 gm ofactive per 100 kg of seed weight. Alternatively, it has been found to bepreferred that the amount of the pesticide be over about 60 gm of theactive ingredient of the pesticide per 100 kg of the seed, and morepreferably over about 80 gm per 100 kg of seed.

The pesticides that are used in the treatment must not inhibitgermination of the seed and should be efficacious in protecting the seedand/or the plant during that time in the target insect's life cycle inwhich it causes injury to the seed or plant. In general, the coatingwill be efficacious for approximately 0 to 120 days after sowing.

The pesticides of the subject invention can be applied to the seed inthe form of a coating. The use of a coating is particularly effective inaccommodating high pesticidal loads, as can be required to treattypically refractory pests, such as lygus, while at the same timepreventing unacceptable phytotoxicity due to the increased pesticidalload.

In addition to the coating layer, the seed may be treated with one ormore of the following ingredients: other pesticides including fungicidesand herbicides; herbicidal safeners; fertilizers and/or biocontrolagents. These ingredients may be added as a separate layer oralternatively may be added in the pesticidal coating layer.

The pesticide formulation may be applied to the seeds using conventionalcoating techniques and machines, such as fluidized bed techniques, theroller mill method, rotostatic seed treaters, and drum coaters. Othermethods, such as spouted beds may also be useful. The seeds may bepresized before coating. After coating, the seeds are typically driedand then transferred to a sizing machine for sizing. Such procedures areknown in the art.

As used herein, the term “insect control agent”, or “gene suppressionagent” refers to a particular RNA molecule consisting of a first RNAsegment and a second RNA segment linked by a third RNA segment. Thefirst and the second RNA segments lie within the length of the RNAmolecule and are substantially inverted repeats of each other and arelinked together by the third RNA segment. The complementarity betweenthe first and the second RNA segments results in the ability of the twosegments to hybridize in vivo and in vitro to form a double strandedmolecule, i.e., a stem, linked together at one end of each of the firstand second segments by the third segment which forms a loop, so that theentire structure forms into a stem and loop structure, or even moretightly hybridizing structures may form into a stem-loop knottedstructure. The first and the second segments correspond invariably andnot respectively to a sense and an antisense sequence with respect tothe target RNA transcribed from the target gene in the target insectpest that is suppressed by the ingestion of the dsRNA molecule. Theinsect control agent can also be a substantially purified (or isolated)nucleic acid molecule and more specifically nucleic acid molecules ornucleic acid fragment molecules thereof from a genomic DNA (gDNA) orcDNA library. Alternatively, the fragments may comprise smalleroligonucleotides having from about 15 to about 250 nucleotide residues,and more preferably, about 15 to about 30 nucleotide residues. The“insect control agent” may also refer to a DNA construct that comprisesthe isolated and purified nucleic acid molecules or nucleic acidfragment molecules thereof from a gDNA or cDNA library. The “insectcontrol agent” may further refer to a microorganism comprising such aDNA construct that comprises the isolated and purified nucleic acidmolecules or nucleic acid fragment molecules thereof from a gDNA or cDNAlibrary. As used herein, the phrase “generating an insect control agent”refers to the methods of employing the recombinant DNA technologiesreadily available in the art (e.g., by Sambrook, et al., 1989) toprepare a recombinant DNA construct transcribing the stabilized dsRNA orsiRNA molecules, to construct a vector transcribing the stabilized dsRNAor siRNA molecules, and/or to transform and generate the cells or themicroorganisms that contain the transcribed, stabilized dsRNA or siRNAmolecules. The method of the present invention provides for theproduction of a dsRNA transcript, the nucleotide sequence of which issubstantially homologous to a targeted RNA sequence encoded by a targetnucleotide sequence within the genome of a target insect pest.

As used herein, the term “genome” as it applies to cells of an insect ora host encompasses not only chromosomal DNA found within the nucleus,but organelle DNA found within subcellular components of the cell. TheDNA's of the present invention introduced into plant cells can thereforebe either chromosomally integrated or organelle-localized. The term“genome” as it applies to bacteria encompasses both the chromosome andplasmids within a bacterial host cell. The DNA's of the presentinvention introduced into bacterial host cells can therefore be eitherchromosomally integrated or plasmid-localized.

Inhibition of target gene expression may be quantified by measuringeither the endogenous target RNA or the protein produced by translationof the target RNA and the consequences of inhibition can be confirmed byexamination of the outward properties of the cell or organism.Techniques for quantifying RNA and proteins are well known to one ofordinary skill in the art. Multiple selectable markers are availablethat confer resistance to ampicillin, bleomycin, chloramphenicol,gentamycin, hygromycin, kanamycin, lincomycin, methotrexate,phosphinothricin, puromycin, spectinomycin, rifampicin, and tetracyclin,and the like.

In certain preferred embodiments gene expression is inhibited by atleast 10%, preferably by at least 33%, more preferably by at least 50%,and yet more preferably by at least 80%. In particularly preferredembodiments of the invention gene expression is inhibited by at least80%, more preferably by at least 90%, more preferably by at least 95%,or by at least 99% within cells in the insect so a significantinhibition takes place. Significant inhibition is intended to refer tosufficient inhibition that results in a detectable phenotype (e.g.,cessation of larval growth, paralysis or mortality, etc.) or adetectable decrease in RNA and/or protein corresponding to the targetgene being inhibited. Although in certain embodiments of the inventioninhibition occurs in substantially all cells of the insect, in otherpreferred embodiments inhibition occurs in only a subset of cellsexpressing the gene. For example, if the gene to be inhibited plays anessential role in cells in the insect alimentary tract, inhibition ofthe gene within these cells is sufficient to exert a deleterious effecton the insect.

The advantages of the present invention may include, but are not limitedto, the following: the ease of introducing dsRNA into the insect cells,the low concentration of dsRNA or siRNA which can be used, the stabilityof dsRNA or siRNA, and the effectiveness of the inhibition. The abilityto use a low concentration of a stabilized dsRNA avoids severaldisadvantages of anti-sense interference. The present invention is notlimited to in vitro use or to specific sequence compositions, to aparticular set of target genes, a particular portion of the targetgene's nucleotide sequence, or a particular transgene or to a particulardelivery method, as opposed to the some of the available techniquesknown in the art, such as antisense and co-suppression. Furthermore,genetic manipulation becomes possible in organisms that are notclassical genetic models.

In practicing the present invention, it is important that the presenceof the nucleotide sequences that are transcribed from the recombinantconstruct are neither harmful to cells of the plant in which they areexpressed in accordance with the invention, nor harmful to an animalfood chain and in particular humans. Because the produce of the plantmay be made available for human ingestion, the down-regulation ofexpression of the target nucleotide sequence occurs only in the insect.

Therefore, in order to achieve inhibition of a target gene selectivelywithin an insect species that it is desired to control, the target geneshould preferably exhibit a low degree of sequence identity withcorresponding genes in a plant or a vertebrate animal. Preferably thedegree of the sequence identity is less than approximately 80%. Morepreferably the degree of the sequence identity is less thanapproximately 70%. Most preferably the degree of the sequence identityis less than approximately 60%.

According to one embodiment of the present invention, there is provideda nucleotide sequence, for which in vitro expression results intranscription of a stabilized RNA sequence that is substantiallyhomologous to an RNA molecule of a targeted gene in an insect thatcomprises an RNA sequence encoded by a nucleotide sequence within thegenome of the insect. Thus, after the stabilized RNA sequenceincorporated in a diet or sprayed on a plant surface is ingested by theinsect, a down-regulation of the nucleotide sequence corresponding tothe target gene in the cells of a target insect is affected. Thedown-regulated nucleotide sequence in the insect results in adeleterious effect on the maintenance, viability, proliferation,reproduction and infectivity of the insect. Therefore, the nucleotidesequence of the present invention may be useful in modulating orcontrolling infestation by a range of insects.

According to another embodiment of the present invention, there isprovided a nucleotide sequence, the expression of which in a microbialcell results in a transcription of an RNA sequence which issubstantially homologous to an RNA molecule of a targeted gene in aninsect that comprises an RNA sequence encoded by a nucleotide sequencewithin the genome of the insect. Thus, after the stabilized RNA sequencecontained in the cell of the microorganism is ingested by the insect, itwill affect down-regulation of the nucleotide sequence of the targetgene in the cells of the insect. The down-regulated nucleotide sequencein the insect results in a deleterious effect on the maintenance,viability, proliferation, reproduction and infestation of the insect.Therefore, the nucleotide sequence of the present invention may beuseful in modulating or controlling infestation by a range of insects.

According to yet another embodiment of the present invention, there isprovided a nucleotide sequence, the expression of which in a plant cellresults in a transcription of an RNA sequence which is substantiallyhomologous to an RNA molecule of a targeted gene in an insect thatcomprises an RNA sequence encoded by a nucleotide sequence within thegenome of the insect. Thus, after the stabilized RNA sequence containedin the cell of the plant is ingested by the insect, it will affectdown-regulation of the nucleotide sequence of the target gene in thecells of the insect. The down-regulated nucleotide sequence in theinsect results in a deleterious effect on the maintenance, viability,proliferation, reproduction and infestation of the insect. Therefore,the nucleotide sequence of the present invention may be useful inmodulating or controlling infestation by a range of insects in plants.

As used herein, the term “substantially homologous” or “substantialhomology”, with reference to a nucleic acid sequence, refers to anucleotide sequence that hybridizes under stringent conditions to thecoding sequence as set forth in any of SEQ ID NO:4 through SEQ ID NO:14and SEQ ID NO:180 through SEQ ID NO:184, or the complements thereof.Sequences that hybridize under stringent conditions to any of SEQ IDNO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184, orthe complements thereof, are those that allow an antiparallel alignmentto take place between the two sequences, and the two sequences are thenable, under stringent conditions, to form hydrogen bonds withcorresponding bases on the opposite strand to form a duplex moleculethat is sufficiently stable under the stringent conditions to bedetectable using methods well known in the art. Such substantiallyhomologous sequences have preferably from about 65% to about 70%sequence identity, or more preferably from about 80% to about 85%sequence identity, or most preferable from about 90% to about 95%sequence identity, to about 99% sequence identity, to the referentnucleotide sequences as set forth in any of SEQ ID NO:4 through SEQ IDNO:14 and SEQ ID NO:180 through SEQ ID NO:184, or the complementsthereof.

As used herein, the term “sequence identity”, “sequence similarity” or“homology” is used to describe sequence relationships between two ormore nucleotide sequences. The percentage of “sequence identity” betweentwo sequences is determined by comparing two optimally aligned sequencesover a comparison window, wherein the portion of the sequence in thecomparison window may comprise additions or deletions (i.e., gaps) ascompared to the reference sequence (which does not comprise additions ordeletions) for optimal alignment of the two sequences. The percentage iscalculated by determining the number of positions at which the identicalnucleic acid base or amino acid residue occurs in both sequences toyield the number of matched positions, dividing the number of matchedpositions by the total number of positions in the window of comparison,and multiplying the result by 100 to yield the percentage of sequenceidentity. A sequence that is identical at every position in comparisonto a reference sequence is said to be identical to the referencesequence and vice-versa. A first nucleotide sequence when observed inthe 5′ to 3′ direction is said to be a “complement” of, or complementaryto, a second or reference nucleotide sequence observed in the 3′ to 5′direction if the first nucleotide sequence exhibits completecomplementarity with the second or reference sequence. As used herein,nucleic acid sequence molecules are said to exhibit “completecomplementarity” when every nucleotide of one of the sequences read 5′to 3′ is complementary to every nucleotide of the other sequence whenread 3′ to 5′. A nucleotide sequence that is complementary to areference nucleotide sequence will exhibit a sequence identical to thereverse complement sequence of the reference nucleotide sequence. Theseterms and descriptions are well defined in the art and are easilyunderstood by those of ordinary skill in the art.

As used herein, a “comparison window” refers to a conceptual segment ofat least 6 contiguous positions, usually about 50 to about 100, moreusually about 100 to about 150, in which a sequence is compared to areference sequence of the same number of contiguous positions after thetwo sequences are optimally aligned. The comparison window may compriseadditions or deletions (i.e. gaps) of about 20% or less as compared tothe reference sequence (which does not comprise additions or deletions)for optimal alignment of the two sequences Those skilled in the artshould refer to the detailed methods used for sequence alignment in theWisconsin Genetics Software Package Release 7.0, Genetics ComputerGroup, 575 Science Drive Madison, Wis., USA) or refer to Ausubel et al.(1998) for a detailed discussion of sequence analysis.

The target gene of the present invention is derived from an insect cellor alternatively, a foreign gene such as a foreign genetic sequence froma virus, a fungus, an insect or a nematode, among others. By “derived”it is intended that a sequence is all or a part of the naturallyoccurring nucleotide sequence of the target gene from the genome of aninsect cell, particularly all or a part of the naturally occurringnucleotide sequence of the capped, spliced, and polyadenylated mRNAexpressed from the naturally occurring DNA sequence as found in the cellif the gene is a structural gene, or the sequence of all or a part of anRNA that is other than a structural gene including but not limited to atRNA, a catalytic RNA, a ribosomal RNA, a micro-RNA, and the like. Asequence is derived from one of these naturally occurring RNA sequencesif the derived sequence is produced based on the nucleotide sequence ofthe native RNA, exhibits from about 80% to about 100% sequence identityto the native sequence, and hybridizes to the native sequence understringent hybridization conditions. In one embodiment, the target genecomprises a nucleotide sequence as set forth in any of SEQ ID NO:4through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184, or thecomplements thereof. Depending on the particular target gene and thedose of dsRNA molecules delivered, this process may provide partial orcomplete loss of function for the target gene, or any desired level ofsuppression in between.

The present invention also provides an artificial DNA sequence capableof being expressed in a cell or microorganism and which is capable ofinhibiting target gene expression in a cell, tissue or organ of aninsect, wherein the artificial DNA sequence at least comprises a dsDNAmolecule coding for one or more different nucleotide sequences, whereineach of the different nucleotide sequences comprises a sense nucleotidesequence and an antisense nucleotide sequence connected by a spacersequence coding for a dsRNA molecule of the present invention. Thespacer sequence constitutes part of the sense nucleotide sequence or theantisense nucleotide sequence and will form within the dsRNA moleculebetween the sense and antisense sequences. The sense nucleotide sequenceor the antisense nucleotide sequence is substantially identical to thenucleotide sequence of the target gene or a derivative thereof or acomplementary sequence thereto. The dsDNA molecule is placed operablyunder the control of a promoter sequence that functions in the cell,tissue or organ of the host expressing the dsDNA to produce dsRNAmolecules. In one embodiment, the artificial DNA sequence may be derivedfrom a nucleotide sequence as set forth in SEQ ID NO:4 through SEQ IDNO:14 and SEQ ID NO:180 through SEQ ID NO:184.

The invention also provides an artificial DNA sequence for expression ina cell of a plant, and that, upon expression of the DNA to RNA andingestion by a target pest achieves suppression of a target gene in acell, tissue or organ of an insect pest. The dsRNA at least comprisesone or multiple structural gene sequences, wherein each of thestructural gene sequences comprises a sense nucleotide sequence and anantisense nucleotide sequence connected by a spacer sequence that formsa loop within the complementary and antisense sequences. The sensenucleotide sequence or the antisense nucleotide sequence issubstantially identical to the nucleotide sequence of the target gene,derivative thereof, or sequence complementary thereto. The one or morestructural gene sequences is placed operably under the control of one ormore promoter sequences, at least one of which is operable in the cell,tissue or organ of a prokaryotic or eukaryotic organism, particularly aninsect. In one embodiment, the artificial DNA sequence comprises fromabout SEQ ID NO:4 through about SEQ ID NO:14 and from about SEQ IDNO:180 through about SEQ ID NO:184 or the complements thereof.

As used herein, the term “non naturally occurring gene”, “non-naturallyoccurring coding sequences”, “artificial sequence”, or “synthetic codingsequences” for transcribing the dsRNA or siRNA of the present inventionor fragments thereof refers to those prepared in a manner involving anysort of genetic isolation or manipulation that results in thepreparation of a coding sequence that transcribes a dsRNA or a siRNA ofthe present invention or fragments thereof. This includes isolation ofthe coding sequence from its naturally occurring state, manipulation ofthe coding sequence as by (1) nucleotide insertion, deletion, orsubstitution, (2) segment insertion, deletion, or substitution, (3)chemical synthesis such as phosphoramidite chemistry and the like,site-specific mutagenesis, truncation of the coding sequence or anyother manipulative or isolative method.

The non-naturally occurring gene sequence or fragment thereof accordingto this aspect of the invention for lygus control may be cloned betweentwo tissue specific promoters, such as two root specific promoters whichare operable in a transgenic plant cell and therein expressed to producemRNA in the transgenic plant cell that form dsRNA molecules thereto. ThedsRNA molecules contained in plant tissues are ingested by an insect sothat the intended suppression of the target gene expression is achieved.

The present invention also provides a method for obtaining a nucleicacid comprising a nucleotide sequence for producing a dsRNA or siRNA ofthe present invention. In a preferred embodiment, the method of thepresent invention for obtaining the nucleic acid comprising: (a) probinga cDNA or gDNA library with a hybridization probe comprising all or aportion of a nucleotide sequence or a homolog thereof from a targetedinsect; (b) identifying a DNA clone that hybridizes with thehybridization probe; (c) isolating the DNA clone identified in step (b);and (d) sequencing the cDNA or gDNA fragment that comprises the cloneisolated in step (c) wherein the sequenced nucleic acid moleculetranscribes all or a substantial portion of the RNA nucleotide acidsequence or a homolog thereof.

In another preferred embodiment, the method of the present invention forobtaining a nucleic acid fragment comprising a nucleotide sequence forproducing a substantial portion of a dsRNA or siRNA of the presentinvention comprising: (a) synthesizing a first and a secondoligonucleotide primers corresponding to a portion of one of thenucleotide sequences from a targeted insect; and (b) amplifying a cDNAor gDNA insert present in a cloning vector using the first and secondoligonucleotide primers of step (a) wherein the amplified nucleic acidmolecule transcribes a substantial portion of the a substantial portionof a dsRNA or siRNA of the present invention.

In practicing the present invention, a target gene may be derived from alygus or any insect species that cause damages to the crop plants andsubsequent yield losses. The present inventors contemplate that severalcriteria may be employed in the selection of preferred target genes. Thegene is one whose protein product has a rapid turnover rate, so thatdsRNA inhibition will result in a rapid decrease in protein levels. Incertain embodiments it is advantageous to select a gene for which asmall drop in expression level results in deleterious effects for theinsect. If it is desired to target a broad range of insect species agene is selected that is highly conserved across these species.Conversely, for the purpose of conferring specificity, in certainembodiments of the invention, a gene is selected that contains regionsthat are poorly conserved between individual insect species, or betweeninsects and other organisms. In certain embodiments it may be desirableto select a gene that has no known homologs in other organisms.

As used herein, the term “derived from” refers to a specified nucleotidesequence that may be obtained from a particular specified source orspecies, albeit not necessarily directly from that specified source orspecies.

In one embodiment, a gene is selected that is expressed in the insectgut. Targeting genes expressed in the gut avoids the requirement for thedsRNA to spread within the insect. Target genes for use in the presentinvention may include, for example, those that share substantialhomologies to the nucleotide sequences of known gut-expressed genes thatencode protein components of the plasma membrane proton V-ATPase (Dow etal., J. Exp. Biol., 200:237-245, 1997; Dow, Bioenerg. Biomemb., 31:75-83, 1999). This protein complex is the sole energizer of epithelialion transport and is responsible for alkalinization of the midgut lumen.The V-ATPase is also expressed in the Malpighian tubule, an outgrowth ofthe insect hindgut that functions in fluid balance and detoxification offoreign compounds in a manner analogous to a kidney organ of a mammal.

In another embodiment, a gene is selected that is essentially involvedin the growth, development, and reproduction of an insect. Exemplarygenes include but are not limited to a CHD3 gene and a β-tubulin gene.The CHD3 gene in Drosophila melanogaster encodes a protein withATP-dependent DNA helicase activity that is involved in chromatinassembly/disassembly in the nucleus. Similar sequences have been foundin diverse organisms such as Arabidopsis thaliana, Caenorhabditiselegans, and Saccharomyces cerevisiae. The beta-tubulin gene familyencodes microtubule-associated proteins that are a constituent of thecellular cytoskeleton. Related sequences are found in such diverseorganisms as Caenorhabditis elegans, and Manduca Sexta.

Other target genes for use in the present invention may include, forexample, those that play important roles in the viability, growth,development, reproduction and infectivity. These target genes may be oneof the house keeping genes, transcription factors and insect specificgenes or lethal knockout mutations in Drosophila. The target genes foruse in the present invention may also be those that are from otherorganisms, e.g., from a nematode (e.g., C. elegans). Additionally, thenucleotide sequences for use in the present invention may also bederived from plant, viral, bacterial or fungal genes whose functionshave been established from literature and the nucleotide sequences ofwhich share substantial similarity with the target genes in the genomeof an insect. According to one aspect of the present invention for lyguscontrol, the target sequences may essentially be derived from thetargeted lygus insect. Some of the exemplary target sequences from cDNAlibrary from lygus that encode lygus proteins or fragments thereof whichare homologues of known proteins may be found in the Sequence Listing.

It is preferred in the practice of the invention to use DNA segmentswhose sequences exhibit at least from about 80% identity, or at leastfrom 90% identity, or at least from 95% identity, or at least from 98%identity, or at least about 100% identity to sequences corresponding togenes or coding sequences within the pest for which control is desired.Sequences less than about 80% identical to a target gene are lesseffective. Inhibition is specific to the pests' gene or genes, thesequence of which corresponds to the dsRNA. Expression of unrelatedgenes is not affected. This specificity allows the selective targetingof pest species, resulting in no effect on other organisms exposed tothe compositions of the present invention. A DNA segment for use in thepresent invention is at least from about 23 to about 100 nucleotides,but less than about 2000 nucleotides, in length.

The invention is not limited to the specific genes described herein butencompasses any gene, the inhibition of which exerts a deleteriouseffect on an insect pest.

For many of the insects that are potential targets for control by thepresent invention, there may be limited information regarding thesequences of most genes or the phenotype resulting from mutation ofparticular genes. Therefore, the present inventors contemplate thatselection of appropriate genes from insect pests for use in the presentinvention may be accomplished through use of information available fromstudy of the corresponding genes in a model organism such in Drosophila,in some other insect species, or even in a nematode species, in a fungalspecies, in a plant species, in which the genes have been characterized.In some cases it will be possible to obtain the sequence of acorresponding gene from a target insect by searching databases such asGenBank using either the name of the gene or the sequence from, forexample, Drosophila, another insect, a nematode, a fungus, or a plantfrom which the gene has been cloned. Once the sequence is obtained, PCRmay be used to amplify an appropriately selected segment of the gene inthe insect for use in the present invention.

In order to obtain a DNA segment from the corresponding gene in aninsect species, PCR primers are designed based on the sequence as foundin lygus or other insects from which the gene has been cloned. Theprimers are designed to amplify a DNA segment of sufficient length foruse in the present invention. DNA (either genomic DNA or cDNA) isprepared from the insect species, and the PCR primers are used toamplify the DNA segment. Amplification conditions are selected so thatamplification will occur even if the primers do not exactly match thetarget sequence. Alternately, the gene (or a portion thereof) may becloned from a gDNA or cDNA library prepared from the insect pestspecies, using the lygus gene or another known insect gene as a probe.Techniques for performing PCR and cloning from libraries are known.Further details of the process by which DNA segments from target insectpest species may be isolated based on the sequence of genes previouslycloned from lygus or other insect species are provided in the Examples.One of ordinary skill in the art will recognize that a variety oftechniques may be used to isolate gene segments from insect pest speciesthat correspond to genes previously isolated from other species. Insectsthat may cause damage in plants generally belong to three categoriesbased upon their methods of feeding and these three categories are,respectively, chewing, sucking and boring insects that belong to theOrders Coleoptera, Lepidoptera, Diptera, Orthoptera, Heteroptera,Ctenophalides, Arachnidiae, and Hymenoptera. It has been found that thepresent method is useful to protect seeds and plants against a widearray of agricultural pests, including insects, mites, fungi, yeasts,molds, bacteria, nematodes, weeds, and parasitic and saprophytic plants,and the like.

When an insect is the target pest for the present invention, such pestsinclude but are not limited to:

from the order Lepidoptera, for example,

-   -   Acleris spp., Adoxophyes spp., Aegeria spp., Agrotis spp.,        Alabama argillaceae, Amylois spp., Anticarsia gemmatalis,        Archips spp, Argyrotaenia spp., Autographa spp., Busseola fusca,        Cadra cautella, Carposina nipponensis, Chilo spp., Choristoneura        spp., Clysia ambiguella, Cnaphalocrocis spp., Cnephasia spp.,        Cochylis spp., Coleophora spp., Crocidolomia binotalis,        Cryptophlebia leucotreta, Cydia spp., Diatraea spp., Diparopsis        castanea, Earias spp., Ephestia spp., Eucosma spp., Eupoecilia        ambiguella, Euproctis spp., Euxoa spp., Grapholita spp., Hedya        nubiferana, Heliothis spp., Hellula undalis, Hyphantria cunea,        Keiferia lycopersicella, Leucoptera scitella, Lithocollethis        spp., Lobesia botrana, Lymantria spp., Lyonetia spp., Malacosoma        spp., Mamestra brassicae, Manduca sexta, Operophtera spp.,        Ostrinia Nubilalis, Pammene spp., Pandemis spp., Panolisflammea,        Pectinophora gossypiella, Phthorimaea operculella, Pieris rapae,        Pieris spp., Plutella xylostella, Prays spp., Scirpophaga spp.,        Sesamia spp., Sparganothis spp., Spodoptera spp., Synanthedon        spp., Thaumetopoea spp., Tortrix spp., Trichoplusia ni and        Yponomeuta spp.;        from the order Coleoptera, for example,    -   Agriotes spp., Anthonomus spp., Atomaria linearis, Chaetocnema        tibialis, Cosmopolites spp., Curculio spp., Dermestes spp.,        Diabrotica spp., Epilachna spp., Eremnus spp., Leptinotarsa        decemlineata, Lissorhoptrus spp., Melolontha spp., Orycaephilus        spp., Otiorhynchus spp., Phlyctinus spp., Popillia spp.,        Psylliodes spp., Rhizopertha spp., Scarabeidae, Sitophilus spp.,        Sitotroga spp., Tenebrio spp., Tribolium spp. and Trogoderna        spp.;        from the order Orthoptera, for example,    -   Blatta spp., Blattella spp., Gryllotalpa spp., Leucophaea        maderae, Locusta spp., Periplaneta ssp., and Schistocerca spp.;        from the order Isoptera, for example,    -   Reticulitemes ssp;        from the order Psocoptera, for example,    -   Liposcelis spp.;        from the order Anoplura, for example,    -   Haematopinus spp., Linognathus spp., Pediculus spp., Pemphigus        spp. and Phylloxera spp.;        from the order Mallophaga, for example,    -   Damalinea spp. and Trichodectes spp.;        from the order Thysanoptera, for example,    -   Franklinella spp., Hercinothrips spp., Taeniothrips spp., Thrips        palmi, Thrips tabaci and Scirtothrips aurantii;        from the order Heteroptera, for example,    -   Cimex spp., Distantiella theobroma, Dysdercus spp., Euchistus        spp., Eurygaster spp., Leptocorisa spp., Nezara spp., Piesma        spp., Rhodnius spp., Sahlbergella singularis, Scotinophara spp.,        Triatoma spp., Miridae family spp. such as Lygus hesperus and        Lygus lineoloris, Lygaeidae family spp. such as Blissus        leucopterus, and Pentatomidae family spp.;        from the order Homoptera, for example,    -   Aleurothrixus floccosus, Aleyrodes brassicae, Aonidiella spp.,        Aphididae, Aphis spp., Aspidiotus spp., Bemisia tabaci,        Ceroplaster spp., Chrysomphalus aonidium, Chrysomphalus        dictyospermi, Coccus hesperidum, Empoasca spp., Eriosoma        larigerum, Erythroneura spp., Gascardia spp., Laodelphax spp.,        Lacanium corni, Lepidosaphes spp., Macrosiphus spp., Myzus spp.,        Nehotettix spp., Nilaparvata spp., Paratoria spp., Pemphigus        spp., Planococcus spp., Pseudaulacaspis spp., Pseudococcus spp.,        Psylla ssp., Pulvinaria aethiopica, Quadraspidiotus spp.,        Rhopalosiphum spp., Saissetia spp., Scaphoideus spp., Schizaphis        spp., Sitobion spp., Trialeurodes vaporariorum, Trioza erytreae        and Unaspis citri;        from the order Hymenoptera, for example,    -   Acromyrmex, Atta spp., Cephus spp., Diprion spp., Diprionidae,        Gilpinia polytoma, Hoplocampa spp., Lasius sppp., Monomorium        pharaonis, Neodiprion spp, Solenopsis spp. and Vespa ssp.;        from the order Diptera, for example,    -   Aedes spp., Antherigona soccata, Bibio hortulanus, Calliphora        erythrocephala, Ceratitis spp., Chrysomyia spp., Culex spp.,        Cuterebra spp., Dacus spp., Drosophila melanogaster, Fannia        spp., Gastrophilus spp., Glossina spp., Hypoderma spp.,        Hyppobosca spp., Liriomysa spp., Lucilia spp., Melanagromyza        spp., Musca ssp., Oestrus spp., Orseolia spp., Oscinella frit,        Pegomyia hyoscyami, Phorbia spp., Rhagoletis pomonella, Sciara        spp., Stomoxys spp., Tabanus spp., Tannia spp. and Tipula spp.,        from the order Siphonaptera, for example,    -   Ceratophyllus spp. und Xenopsylla cheopis and        from the order Thysanura, for example,    -   Lepisma saccharina.

The present invention is particularly effective for controlling speciesof insects that pierce and/or suck the fluids from the cells and tissuesof plants, including but not limited to plant bugs in the Miridae familysuch as western tarnished plant bugs (Lygus hesperus species), tarnishedplant bugs (Lygus lineolaris species), and pale legume bugs (Lyguselisus) and stinkbugs (Pentatomidae family species).

Modifications of the methods disclosed herein are also surprisinglyparticularly useful in controlling crop pests within the orderlepidopteran.

The present invention provides stabilized dsRNA or siRNA molecules forcontrol of insect infestations. The dsRNA or siRNA nucleotide sequencescomprise double strands of polymerized ribonucleotide and may includemodifications to either the phosphate-sugar backbone or the nucleoside.Modifications in RNA structure may be tailored to allow specific geneticinhibition.

In one embodiment, the dsRNA molecules may be modified through anenzymatic process so the siRNA molecules may be generated. The siRNA canefficiently mediate the down-regulation effect for some target genes insome insects. This enzymatic process may be accomplished by utilizing anRNAse III enzyme or a DICER enzyme, present in the cells of an insect, avertebrate animal, a fungus or a plant in the eukaryotic RNAi pathway(Elbashir et al., 2002, Methods, 26(2):199-213; Hamilton and Baulcombe,1999, Science 286:950-952). This process may also utilize a recombinantDICER or RNAse III introduced into the cells of a target insect throughrecombinant DNA techniques that are readily known to the skilled in theart. Both the DICER enzyme and RNAse III, being naturally occurring inan insect or being made through recombinant DNA techniques, cleavelarger dsRNA strands into smaller oligonucleotides. The DICER enzymesspecifically cut the dsRNA molecules into siRNA pieces each of which isabout 19-25 nucleotides in length while the RNAse III enzymes normallycleave the dsRNA molecules into 12-15 base-pair siRNA. The siRNAmolecules produced by the either of the enzymes have 2 to 3 nucleotide3′ overhangs, and 5′ phosphate and 3′ hydroxyl termini. The siRNAmolecules generated by RNAse III enzyme are the same as those producedby Dicer enzymes in the eukaryotic RNAi pathway and are hence thentargeted and degraded by an inherent cellular RNA-degrading mechanismafter they are subsequently unwound, separated into single-stranded RNAand hybridize with the RNA sequences transcribed by the target gene.This process results in the effective degradation or removal of the RNAsequence encoded by the nucleotide sequence of the target gene in theinsect. The outcome is the silencing of a particularly targetednucleotide sequence within the insect.

Inhibition of a target gene using the stabilized dsRNA technology of thepresent invention is sequence-specific in that nucleotide sequencescorresponding to the duplex region of the RNA are targeted for geneticinhibition. RNA containing a nucleotide sequences identical to a portionof the target gene is preferred for inhibition. RNA sequences withinsertions, deletions, and single point mutations relative to the targetsequence have also been found to be effective for inhibition. Inperformance of the present invention, it is preferred that theinhibitory dsRNA and the portion of the target gene share at least fromabout 80% sequence identity, or from about 90% sequence identity, orfrom about 95% sequence identity, or from about 99% sequence identity,or even about 100% sequence identity. Alternatively, the duplex regionof the RNA may be defined functionally as a nucleotide sequence that iscapable of hybridizing with a portion of the target gene transcript. Aless than full length sequence exhibiting a greater homology compensatesfor a longer less homologous sequence. The length of the identicalnucleotide sequences may be at least 25, 50, 100, 200, 300, 400, 500 or1000 bases. Normally, a sequence of greater than 20-100 nucleotidesshould be used, though a sequence of greater than about 200-300nucleotides would be preferred, and a sequence of greater than 500-1000nucleotides would be especially preferred depending on the size of thetarget gene. The invention has the advantage of being able to toleratesequence variations that might be expected due to genetic mutation,strain polymorphism, or evolutionary divergence. The introduced nucleicacid molecule may not need to be absolute homology, may not need to befull length, relative to either the primary transcription product orfully processed mRNA of the target gene. Therefore, those skilled in theart need to realize that, as disclosed herein, 100% sequence identitybetween the RNA and the target gene is not required to practice thepresent invention.

The dsRNA molecules may be synthesized either in vivo or in vitro. ThedsRNA may be formed by a single self-complementary RNA strand or twocomplementary RNA strands. Endogenous RNA polymerase of the cell maymediate transcription in vivo, or cloned RNA polymerase can be used fortranscription in vivo or in vitro. Inhibition may be targeted byspecific transcription in an organ, tissue, or cell type; stimulation ofan environmental condition (e.g., infection, stress, temperature,chemical inducers); and/or engineering transcription at a developmentalstage or age. The RNA strands may or may not be polyadenylated; the RNAstrands may or may not be capable of being translated into a polypeptideby a cell's translational apparatus.

The RNA, dsRNA, siRNA, or mRNA of the present invention may be producedchemically or enzymatically by one skilled in the art through manual orautomated reactions or in vivo in another organism. RNA may also beproduced by partial or total organic synthesis, any modifiedribonucleotide can be introduced by in vitro enzymatic or organicsynthesis. The RNA may be synthesized by a cellular RNA polymerase or abacteriophage RNA polymerase (e.g., T3, T7, SP6). The use and productionof an expression construct are known in the art (see, for example, WO97/32016; U.S. Pat. Nos. 5,593,874, 5,698,425, 5,712,135, 5,789,214, and5,804,693). If synthesized chemically or by in vitro enzymaticsynthesis, the RNA may be purified prior to introduction into the cell.For example, RNA can be purified from a mixture by extraction with asolvent or resin, precipitation, electrophoresis, chromatography, or acombination thereof. Alternatively, the RNA may be used with no or aminimum of purification to avoid losses due to sample processing. TheRNA may be dried for storage or dissolved in an aqueous solution. Thesolution may contain buffers or salts to promote annealing, and/orstabilization of the duplex strands.

For transcription from a transgene in vivo or an expression construct, aregulatory region (e.g., promoter, enhancer, silencer, andpolyadenylation) may be used to transcribe the RNA strand (or strands).Therefore, in one embodiment, the nucleotide sequences for transcriptionto an RNA molecules may be operably linked to one or more promotersequences functional in a microorganism, a fungus or a plant host.Ideally, the nucleotide sequences are placed under the control of anendogenous promoter, normally resident in the host genome. Thenucleotide sequence of the present invention, under the control of anoperably linked promoter sequence, may further be flanked by additionalsequences that advantageously affect its transcription and/or thestability of a resulting transcript. Such sequences are generallylocated upstream of the operably linked promoter and/or downstream ofthe 3′ end of the expression construct and may occur both upstream ofthe promoter and downstream of the 3′ end of the expression construct,although such an upstream sequence only is also contemplated.

In another embodiment, the nucleotide sequence of the present inventionmay comprises an inverted repeat separated by a “spacer sequence”. Thespacer sequence may be a region comprising any sequence of nucleotidesthat facilitates secondary structure formation between each repeat,where this is required. In one embodiment of the present invention, thespacer sequence is part of the sense or antisense coding sequence formRNA. The spacer sequence may alternatively comprise any combination ofnucleotides or homologues thereof that are capable of being linkedcovalently to a nucleic acid molecule. The spacer sequence may comprisea sequence of nucleotides of at least about 10-100 nucleotides inlength, or alternatively at least about 100-200 nucleotides in length,at least about 200-400 nucleotides in length, or at least about 400-500nucleotides in length.

For the purpose of the present invention, the dsRNA or siRNA moleculesmay be obtained from lygus by polymerase chain (PCR) amplification of atarget lygus gene sequence derived from lygus gDNA or cDNA, a librarymade from samples of gDNA or cDNA, or portions thereof. Lygus eggs,nymphs, and adults may be prepared using methods known in the art andDNA/RNA may be extracted. Lygus bugs at various developmental stages maybe used for the purpose of the present invention for DNA/RNA extraction.Genomic DNA or cDNA libraries generated from lygus may be used for PCRamplification for production of the dsRNA or siRNA.

The target genes may be then be PCR amplified and sequenced using themethods readily available in the art. One skilled in the art may be ableto modify the PCR conditions to ensure optimal PCR product formation.The confirmed PCR product may be used as a template for in vitrotranscription to generate sense and antisense RNA with the includedminimal promoters.

The present inventors contemplate that nucleic acid sequences identifiedand isolated from any insect species in the insect kingdom may be usedin the present invention for control of lygus and another targetedinsects. In one aspect of the present invention, the nucleic acid may bederived from a species from a hemipteran species. Specifically, thenucleic acid may be derived from Western Tarnished Palnt bugs belongingto the genus Lygus (Hemiptera Miridae) and more specifically the nucleicacid molecules of the present invention may be derived from speciesLygus hesperus. The isolated nucleic acids may be useful, for example,in identifying a target gene and in constructing a recombinant vectorthat produce stabilized dsRNAs or siRNAs of the present invention forprotecting plants from lygus insect infestations.

Therefore, in one embodiment, the present invention comprises isolatedand purified nucleotide sequences from Lygus that may be used as theinsect control agents. The isolated and purified nucleotide sequencescomprise those as set forth in SEQ ID NO:4 through SEQ ID NO:14 and SEQID NO:180 through SEQ ID NO:184.

The nucleic acids from Lygus that may be used in the present inventionmay also comprise isolated and substantially purified EST nucleic acidmolecules or nucleic acid fragment molecules thereof. EST nucleic acidmolecules may encode significant portions of, or indeed most of, thepolypeptides. Alternatively, the fragments may comprise smalleroligonucleotides having from about 15 to about 250 nucleotide residues,and more preferably, about 15 to about 30 nucleotide residues.Alternatively, the nucleic acid molecules for use in the presentinvention may be from cDNA libraries from Lygus, or from any otherinvertebrate pest species.

As used herein, the phrase “a substantially purified nucleic acid”, “anartificial sequence”, “an isolated and substantially purified nucleicacid”, or “an isolated and substantially purified nucleotide sequence”refers to a nucleic acid that is no longer accompanied by some ofmaterials with which it is associated in its natural state or to anucleic acid the structure of which is not identical to that of any ofnaturally occurring nucleic acid. Examples of a substantially purifiednucleic acid include: (1) DNAs which have the sequence of part of anaturally occurring genomic DNA molecules but are not flanked by twocoding sequences that flank that part of the molecule in the genome ofthe organism in which it naturally occurs; (2) a nucleic acidincorporated into a vector or into the genomic DNA of a prokaryote oreukaryote in a manner such that the resulting molecule is not identicalto any naturally occurring vector or genomic DNA; (3) a separatemolecule such as a cDNA, a genomic fragment, a fragment produced bypolymerase chain reaction (PCR), or a restriction fragment; (4)recombinant DNAs; and (5) synthetic DNAs. A substantially purifiednucleic acid may also be comprised of one or more segments of cDNA,genomic DNA or synthetic DNA.

Nucleic acid molecules and fragments thereof. Lygus, or otherinvertebrate pest species may be employed to obtain other nucleic acidmolecules from other species for use in the present invention to producedesired dsRNA and siRNA molecules. Such nucleic acid molecules includethe nucleic acid molecules that encode the complete coding sequence of aprotein and promoters and flanking sequences of such molecules. Inaddition, such nucleic acid molecules include nucleic acid moleculesthat encode for gene family members. Such molecules can be readilyobtained by using the above-described nucleic acid molecules orfragments thereof to screen cDNA or gDNA libraries obtained from Lygushesperus.

Nucleic acid molecules and fragments thereof from Lygus may also beemployed to obtain other nucleic acid molecules such as nucleic acidhomologues for use in the present invention to produce desired dsRNA andsiRNA molecules. Such homologues include the nucleic acid molecules thatencode, in whole or in part, protein homologues of other species, plantsor other organisms. Such molecules can be readily obtained by using theabove-described nucleic acid molecules or fragments thereof to screenEST, cDNA or gDNA libraries. Methods for forming such libraries are wellknown in the art. Such homologue molecules may differ in theirnucleotide sequences from those found in one or more of SEQ ID NO:4through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184 orcomplements thereof disclosed herein, because complete complementarityis not needed for stable hybridization. These nucleic acid moleculesalso include molecules that, although capable of specificallyhybridizing with the nucleic acid molecules may lack completecomplementarity. In a particular embodiment, methods for 3′ or 5′ RACEmay be used to obtain such sequences (Frohman, M. A. et al., Proc. Natl.Acad. Sci. (U.S.A.) 85:8998-9002 (1988); Ohara, O. et al., Proc. Natl.Acad. Sci. (U.S.A.) 86:5673-5677 (1989)). In general, any of the abovedescribed nucleic acid molecules or fragments may be used to generatedsRNAs or siRNAs that are suitable for use in a diet, in a spray-onmixer or in a recombinant DNA construct of the present invention.

As used herein, the phrase “coding sequence”, “structural nucleotidesequence” or “structural nucleic acid molecule” refers to a nucleotidesequence that is translated into a polypeptide, usually via mRNA, whenplaced under the control of appropriate regulatory sequences. Theboundaries of the coding sequence are determined by a translation startcodon at the 5′-terminus and a translation stop codon at the3′-terminus. A coding sequence can include, but is not limited to,genomic DNA, cDNA, EST and recombinant nucleotide sequences.

The term “recombinant DNA” or “recombinant nucleotide sequence” refersto DNA that contains a genetically engineered modification throughmanipulation via mutagenesis, restriction enzymes, and the like.

EST nucleic acid molecules or fragment EST nucleic acid molecules orother nucleic acid molecules from lygus are capable of specificallyhybridizing to other nucleic acid molecules under certain circumstances.As used herein, two nucleic acid molecules are said to be capable ofspecifically hybridizing to one another if the two molecules are capableof forming an anti-parallel, double-stranded nucleic acid structure. Anucleic acid molecule is said to be the complement of another nucleicacid molecule if they exhibit complete complementarity. Two moleculesare said to be “minimally complementary” if they can hybridize to oneanother with sufficient stability to permit them to remain annealed toone another under at least conventional “low-stringency” conditions.Similarly, the molecules are said to be complementary if they canhybridize to one another with sufficient stability to permit them toremain annealed to one another under conventional “high-stringency”conditions. Conventional stringency conditions are described bySambrook, et al., 1989; and by Haymes, et al. In: Nucleic AcidHybridization, A Practical Approach, IRL Press, Washington, D.C. (1985).

Departures from complete complementarity are therefore permissible, aslong as such departures do not completely preclude the capacity of themolecules to form a double-stranded structure. Thus, in order for an ESTnucleic acid molecule or fragment EST nucleic acid molecule to serve asa primer or probe it needs only be sufficiently complementary insequence to be able to form a stable double-stranded structure under theparticular solvent and salt concentrations employed.

Appropriate stringency conditions which promote DNA hybridization are,for example, 6.0× sodium chloride/sodium citrate (SSC) at about 45° C.,followed by a wash of 2.0×SSC at 50° C., are known to those skilled inthe art or can be found in Current Protocols in Molecular Biology, JohnWiley & Sons, N.Y. (1989), 6.3.1-6.3.6. For example, the saltconcentration in the wash step can be selected from a low stringency ofabout 2.0×SSC at 50° C. to a high stringency of about 0.2×SSC at 50° C.In addition, the temperature in the wash step can be increased from lowstringency conditions at room temperature, about 22° C., to highstringency conditions at about 65° C. Both temperature and salt may bevaried, or either the temperature or the salt concentration may be heldconstant while the other variable is changed.

A nucleic acid for use in the present invention may specificallyhybridize to one or more of nucleic acid molecules from lygus orcomplements thereof under moderately stringent conditions, for exampleat about 2.0×SSC and about 65° C. A nucleic acid for use in the presentinvention will include those nucleic acid molecules that specificallyhybridize to one or more of the nucleic acid molecules disclosed thereinas set forth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180through SEQ ID NO:184 or complements thereof under high stringencyconditions. Preferably, a nucleic acid for use in the present inventionwill exhibit at least from about 80%, or at least from about 90%, or atleast from about 95%, or at least from about 98% or even about 100%sequence identity with one or more nucleic acid molecules as set forthin SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQ IDNO:184, or as disclosed herein; or a nucleic acid for use in the presentinvention will exhibit at from about 80%, or at least from about 90%, orat least from about 95%, or at least from about 98% or even about 100%sequence identity with one or more nucleic acid molecules as set forthin SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 through SEQ IDNO:184 isolated from the genomic DNA of an insect pest.

All or a substantial portion of the nucleic acids from lygus may be usedto isolate cDNAs, gDNAs and nucleic acids encoding Lygus proteinhomologues or fragments thereof from the same or other species. Thedetailed descriptions of the techniques on isolation and identificationof nucleic acids of the present invention from cDNA or gDNA librariesare disclosed in the examples.

Nucleic acids of the present invention may also be synthesized, eithercompletely or in part, especially where it is desirable to provideplant-preferred sequences, by well-known techniques as described in thetechnical literature. See, e.g., Carruthers et al., Cold Spring HarborSymp. Quant. Biol. 47:411-418 (1982), and Adams et al., J. Am. Chem.Soc. 105:661 (1983). Thus, all or a portion of the nucleic acids of thepresent invention may be synthesized using codons preferred by aselected host. Species-preferred codons may be determined, for example,from the codons used most frequently in the proteins expressed in aparticular host species. Other modifications of the nucleotide sequencesmay result in mutants having slightly altered activity.

The present invention provides in part a delivery system for thedelivery of insect control agents to insects. The stabilized dsRNA orsiRNA molecules of the present invention may be directly introduced intothe cells of an insect, or introduced into an extracellular cavity,interstitial space, lymph system, digestive system, into the circulationof the insect through oral ingestion or other means that one skilled inthe art may employ. Methods for oral introduction may include directmixing of RNA with food of the insect, as well as engineered approachesin which a species that is used as food is engineered to express thedsRNA or siRNA, then fed to the insect to be affected. In oneembodiment, for example, the dsRNA or siRNA molecules may beincorporated into, or overlaid on the top of, the insect's diet. Inanother embodiment, the RNA may be sprayed onto a plant surface. Instill another embodiment, the dsRNA or siRNA may be expressed bymicroorganisms and the microorganisms may be applied onto a plantsurface or introduced into a root, stem by a physical means such as aninjection. In still another embodiment, a plant may be geneticallyengineered to express the dsRNA or siRNA in an amount sufficient to killthe insects known to infect the plant.

Specifically, in practicing the present invention in lygus, thestabilized dsRNA or siRNA may be introduced in the midgut inside theinsect and achieve the desired inhibition of the targeted genes. ThedsRNA or siRNA molecules may be incorporated into a diet or be overlaidon the diet as discussed above and may be ingested by the insects. Inany event, the dsRNA's of the present invention are provided in the dietof the target pest. The target pest of the present invention willexhibit a digestive tract pH from about 4.5 to about 9.5, or from about5 to about 8.5, or from about 6 to about 8, or from about 6.5 to about7.7, or about 7.0. The digestive tract of a target pest is definedherein as the location within the pest that food that is ingested by thetarget pest is exposed to an environment that is favorable for theuptake of the dsRNA molecules of the present invention without sufferinga pH so extreme that the hydrogen bonding between the double-strands ofthe dsRNA are caused to dissociate and form single stranded molecules.

Further, for the purpose of controlling insect infestations in plants,delivery of insect control dsRNAs to the surfaces of a plant via aspray-on application affords another means of protecting the plants. Inthis instance, a bacterium engineered to produce and accumulate dsRNAsmay be fermented and the products of the fermentation formulated as aspray-on product compatible with common agricultural practices. Theformulations may include the appropriate stickers and wetters requiredfor efficient foliar coverage as well as UV protectants to protectdsRNAs from UV damage. Such additives are commonly used in thebioinsecticide industry and are well known to those skilled in the art.It is also anticipated that dsRNA's produced by chemical or enzymaticsynthesis may be formulated in a manner consistent with commonagricultural practices and used as spray-on products for controllinginsect infestations. The formulations may include the appropriatestickers and wetters required for efficient foliar coverage as well asUV protectants to protect dsRNAs from UV damage. Such additives arecommonly used in the bioinsecticide industry and are well known to thoseskilled in the art. Such applications could be combined with otherspray-on insecticide applications, biologically based or not, to enhanceplant protection from insect feeding damage.

The present inventors contemplate that bacterial strains producinginsecticidal proteins may be used to produce dsRNAs for insect controlpurposes. These strains may exhibit improved insect control properties.A variety of different bacterial hosts may be used to produce insectcontrol dsRNAs. Exemplary bacteria may include E. coli, B.thuringiensis, Pseudomonas sp., Photorhabdus sp., Xenorhabdus sp.,Serratia entomophila and related Serratia sp., B. sphaericus, B. cereus,B. laterosporus, B. popilliae, Clostridium bifermentans and otherClostridium species, or other spore-forming gram-positive bacteria.

The present invention also relates to recombinant DNA constructs forexpression in a microorganism. Exogenous nucleic acids from which an RNAof interest is transcribed can be introduced into a microbial host cell,such as a bacterial cell or a fungal cell, using methods known in theart.

The nucleotide sequences of the present invention may be introduced intoa wide variety of prokaryotic and eukaryotic microorganism hosts toproduce the stabilized dsRNA or siRNA molecules. The term“microorganism” includes prokaryotic and eukaryotic microbial speciessuch as bacteria and fungi. Fungi include yeasts and filamentous fungi,among others. Illustrative prokaryotes, both Gram-negative andGram-positive, include Enterobacteriaceae, such as Escherichia, Erwinia,Shigella, Salmonella, and Proteus; Bacillaceae; Rhizobiceae, such asRhizobium; Spirillaceae, such as photobacterium, Zymomonas, Serratia,Aeromonas, Vibrio, Desulfovibrio, Spirillum; Lactobacillaceae;Pseudomonadaceae, such as Pseudomonas and Acetobacter; Azotobacteraceae,Actinomycetales, and Nitrobacteraceae. Among eukaryotes are fungi, suchas Phycomycetes and Ascomycetes, which includes yeast, such asSaccharomyces and Schizosaccharomyces; and Basidiomycetes yeast, such asRhodotorula, Aureobasidium, Sporobolomyces, and the like.

For the purpose of plant protection against insects, a large number ofmicroorganisms known to inhabit the phylloplane (the surface of theplant leaves) and/or the rhizosphere (the soil surrounding plant roots)of a wide variety of important crops may also be desirable host cellsfor manipulation, propagation, storage, delivery and/or mutagenesis ofthe disclosed recombinant constructs. These microorganisms includebacteria, algae, and fungi. Of particular interest are microorganisms,such as bacteria, e.g., genera Bacillus (including the species andsubspecies B. thuringiensis kurstaki HD-1, B. thuringiensis kurstakiHD-73, B. thuringiensis sotto, B. thuringiensis berliner, B.thuringiensis thuringiensis, B. thuringiensis tolworthi, B.thuringiensis dendrolimus, B. thuringiensis alesti, B. thuringiensisgalleriae, B. thuringiensis aizawai, B. thuringiensis subtoxicus, B.thuringiensis entomocidus, B. thuringiensis tenebrionis and B.thuringiensis san diego); Pseudomonas, Erwinia, Serratia, Klebsiella,Zanthomonas, Streptomyces, Rhizobium, Rhodopseudomonas, Methylophilius,Agrobacterium, Acetobacter, Lactobacillus, Arthrobacter, Azotobacter,Leuconostoc, and Alcaligenes; fungi, particularly yeast, e.g., generaSaccharomyces, Cryptococcus, Kluyveromyces, Sporobolomyces, Rhodotorula,and Aureobasidium. Of particular interest are such phytosphere bacterialspecies as Pseudomonas syringae, Pseudomonas fluorescens, Serratiamarcescens, Acetobacter xylinum, Agrobacterium tumefaciens, Rhodobactersphaeroides, Xanthomonas campestris, Rhizobium melioti, Alcaligeneseutrophus, and Azotobacter vinlandii; and phytosphere yeast species suchas Rhodotorula rubra, R. glutinis, R. marina, R. aurantiaca,Cryptococcus albidus, C. diffluens, C. laurentii, Saccharomyces rosei,S. pretoriensis, S. cerevisiae, Sporobolomyces roseus, S. odorus,Kluyveromyces veronae, and Aureobasidium pollulans.

A bacterial recombinant DNA vector may be a linear or a closed circularplasmid. The vector system may be a single vector or plasmid or two ormore vectors or plasmids that together contain the total DNA to beintroduced into the genome of the bacterial host. In addition, thebacterial vector may be an expression vector. Nucleic acid molecules asset forth in SEQ ID NO:4 through SEQ ID NO:14 and SEQ ID NO:180 throughSEQ ID NO:184 or fragments thereof can, for example, be suitablyinserted into a vector under the control of a suitable promoter thatfunctions in one or more microbial hosts to drive expression of a linkedcoding sequence or other DNA sequence. Many vectors are available forthis purpose, and selection of the appropriate vector will depend mainlyon the size of the nucleic acid to be inserted into the vector and theparticular host cell to be transformed with the vector. Each vectorcontains various components depending on its function (amplification ofDNA or expression of DNA) and the particular host cell with which it iscompatible. The vector components for bacterial transformation generallyinclude, but are not limited to, one or more of the following: a signalsequence, an origin of replication, one or more selectable marker genes,and an inducible promoter allowing the expression of exogenous DNA.

Expression and cloning vectors generally contain a selection gene, alsoreferred to as a selectable marker. This gene encodes a proteinnecessary for the survival or growth of transformed host cells grown ina selective culture medium. Typical selection genes encode proteins that(a) confer resistance to antibiotics or other toxins, e.g., ampicillin,neomycin, methotrexate, or tetracycline, (b) complement auxotrophicdeficiencies, or (c) supply critical nutrients not available fromcomplex media, e.g., the gene encoding D-alanine racemase for Bacilli.Those cells that are successfully transformed with a heterologousprotein or fragment thereof produce a protein conferring drug resistanceand thus survive the selection regimen.

An expression vector for producing a mRNA can also contains an induciblepromoter that is recognized by the host bacterial organism and isoperably linked to the nucleic acid encoding, for example, the nucleicacid molecule coding the D. v. virgifera mRNA or fragment thereof ofinterest. Inducible promoters suitable for use with bacterial hostsinclude β-lactamase promoter, E. coli λ phage P_(L) and P_(R) promoters,and E. coli galactose promoter, arabinose promoter, alkaline phosphatasepromoter, tryptophan (trp) promoter, and the lactose operon promoter andvariations thereof (Chang et al., Nature 275:615, 1978; Goeddel et al.,Nature 281:544, 1979; Guzman et al., J. Bacteriol. 174:7716-7728, 1992;Goeddel, Nucleic Acids Res. 8:4057, 1980; EP 36,776) and hybridpromoters such as the tac promoter (deBoer et al., Proc. Natl. Acad. Sci(USA) 80:21-25, 1983). However, other known bacterial induciblepromoters are suitable (Siebenlist et al., Cell 20:269, 1980).

The term “operably linked”, as used in reference to a regulatorysequence and a structural nucleotide sequence, means that the regulatorysequence causes regulated expression of the linked structural nucleotidesequence. “Regulatory sequences” or “control elements” refer tonucleotide sequences located upstream (5′ noncoding sequences), within,or downstream (3′ non-translated sequences) of a structural nucleotidesequence, and which influence the timing and level or amount oftranscription, RNA processing or stability, or translation of theassociated structural nucleotide sequence. Regulatory sequences mayinclude promoters, translation leader sequences, introns, enhancers,stem-loop structures, repressor binding sequences, and polyadenylationrecognition sequences and the like.

Alternatively, the expression constructs can be integrated into thebacterial genome with an integrating vector. Integrating vectorstypically contain at least one sequence homologous to the bacterialchromosome that allows the vector to integrate. Integrations appear toresult from recombinations between homologous DNA in the vector and thebacterial chromosome. For example, integrating vectors constructed withDNA from various Bacillus strains integrate into the Bacillus chromosome(EE.P. 0 127 328). Integrating vectors may also be comprised ofbacteriophage or transposon sequences. Suicide vectors are also known inthe art.

Construction of suitable vectors containing one or more of theabove-listed components employs standard recombinant DNA techniques.Isolated plasmids or DNA fragments are cleaved, tailored, and re-ligatedin the form desired to generate the plasmids required. Examples ofavailable bacterial expression vectors include, but are not limited to,the multifunctional E. coli cloning and expression vectors such asBluescript™ (Stratagene, La Jolla, Calif.), in which, for example, a D.v. virgifera protein or fragment thereof, may be ligated into the vectorin frame with sequences for the amino-terminal Met and the subsequent 7residues of β-galactosidase so that a hybrid protein is produced; pINvectors (Van Heeke and Schuster J. Biol. Chem. 264:5503-5509, 1989); andthe like.

A yeast recombinant construct can typically include one or more of thefollowing: a promoter sequence, fusion partner sequence, leadersequence, transcription termination sequence, a selectable marker. Theseelements can be combined into an expression cassette, which may bemaintained in a replicon, such as an extrachromosomal element (e.g.,plasmids) capable of stable maintenance in a host, such as yeast orbacteria. The replicon may have two replication systems, thus allowingit to be maintained, for example, in yeast for expression and in aprokaryotic host for cloning and amplification. Examples of suchyeast-bacteria shuttle vectors include YEp24 (Botstein et al., Gene,8:17-24 (1979)), pCl/1 (Brake et al., Proc. Natl. Acad. Sci USA,81:4642-4646, 1984)), and YRp17 (Stinchcomb et al., J. Mol. Biol.,158:157, 1982). In addition, a replicon may be either a high or low copynumber plasmid. A high copy number plasmid will generally have a copynumber ranging from about 5 to about 200, and typically about 10 toabout 150. A host containing a high copy number plasmid will preferablyhave at least about 10, and more preferably at least about 20.

Examples of transcription terminator sequence and other yeast-recognizedtermination sequences, such as those coding for glycolytic enzymes, areknown to those of skill in the art.

Alternatively, the expression constructs can be integrated into a yeastgenome with an integrating vector. Integrating vectors typically containat least one sequence homologous to a yeast chromosome that allows thevector to integrate, and preferably contain two homologous sequencesflanking the expression construct. Integrations appear to result fromrecombinations between homologous DNA in the vector and the yeastchromosome (Orr-Weaver et al., Methods in Enzymol., 101:228-245, 1983).An integrating vector may be directed to a specific locus in yeast byselecting the appropriate homologous sequence for inclusion in thevector. See Orr-Weaver et al., supra. The chromosomal sequences includedin the vector can occur either as a single segment in the vector, whichresults in the integration of the entire vector, or as two segmentshomologous to adjacent segments in the chromosome and flanking theexpression construct in the vector, which results in the stableintegration of only the expression construct.

The present invention also contemplates transformation of a nucleotidesequence of the present invention into a plant to achieve pestinhibitory levels of expression of one or more dsRNA molecules. Atransformation vector can be readily prepared using methods available inthe art. The transformation vector comprises one or more nucleotidesequences that is/are capable of being transcribed to an RNA moleculeand that is/are substantially homologous and/or complementary to one ormore nucleotide sequences encoded by the genome of the insect, such thatupon uptake of the RNA transcribed from the one or more nucleotidesequences molecules by the insect, there is down-regulation ofexpression of at least one of the respective nucleotide sequences of thegenome of the insect.

The transformation vector may further mean a dsDNA construct and mayalso be regarded inter alia as a recombinant molecule, an insect controlagent, a genetic molecule or a chimeric genetic construct. A chimericgenetic construct of the present invention may comprise, for example,nucleotide sequences encoding one or more antisense transcripts, one ormore sense transcripts, one or more of each of the afore-mentioned,wherein all or part of a transcript therefrom is homologous to all orpart of an RNA molecule comprising an RNA sequence encoded by anucleotide sequence within the genome of an insect.

In one embodiment the plant transformation vector is an isolated andpurified DNA molecule comprising a promoter operatively linked to one ormore nucleotide sequences of the present invention. The nucleotidesequence is selected from the group consisting of SEQ ID NO:4 throughSEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184. The nucleotidesequence includes a segment coding all or part of an RNA present withina targeted pest RNA transcript and may comprise inverted repeats of allor a part of a targeted pest RNA. The DNA molecule comprising theexpression vector may also contain a functional intron sequencepositioned either upstream of the coding sequence or even within thecoding sequence, and may also contain a five prime (5′) untranslatedleader sequence (i.e., a UTR or 5′-UTR) positioned between the promoterand the point of translation initiation.

A plant transformation vector may contain sequences from more than onegene, thus allowing production of more than one dsRNA for inhibitingexpression of two or more genes in cells of a target pest. One skilledin the art will readily appreciate that segments of DNA whose sequencecorresponds to that present in different genes can be combined into asingle composite DNA segment for expression in a transgenic plant.Alternatively, a plasmid of the present invention already containing atleast one DNA segment can be modified by the sequential insertion ofadditional DNA segments between the enhancer and promoter and terminatorsequences. In the insect control agent of the present invention designedfor the inhibition of multiple genes, the genes to be inhibited can beobtained from the same insect species in order to enhance theeffectiveness of the insect control agent. In certain embodiments, thegenes can be derived from different insects in order to broaden therange of insects against which the agent is effective. When multiplegenes are targeted for suppression or a combination of expression andsuppression, a polycistronic DNA element can be fabricated asillustrated and disclosed in Fillatti, Application Publication No. U.S.2004-0029283 A1.

Where a nucleotide sequence of the present invention is to be used totransform a plant, a promoter exhibiting the ability to drive expressionof the coding sequence in that particular species of plant is selected.Promoters that function in different plant species are also well knownin the art. Promoters useful for expression of polypeptides in plantsare those that are inducible, viral, synthetic, or constitutive asdescribed in Odell et al. (Nature 313:810-812, 1985), and/or promotersthat are temporally regulated, spatially regulated, andspatio-temporally regulated. Preferred promoters include the enhancedCaMV35S promoters, and the FMV35S promoter. For the purpose of thepresent invention, e.g., for optimum control of species that feed onroots, it is preferable to achieve the highest levels of expression ofthese genes within the roots of plants. A number of root-enhancedpromoters have been identified and are known in the art. (Lu et al., J.Plant Phys., 156(2):277-283, 2000; U.S. Pat. No. 5,837,848; U.S. Pat.No. 6,489,542). Wound specific promoters may be optimum for expressionof dsRNA's for controlling lygus bugs and other piercing and suckinginsects and the like.

A recombinant DNA vector or construct of the present invention willtypically comprise a selectable marker that confers a selectablephenotype on plant cells. Selectable markers may also be used to selectfor plants or plant cells that contain the exogenous nucleic acidsencoding polypeptides or proteins of the present invention. The markermay encode biocide resistance, antibiotic resistance (e.g., kanamycin,G418 bleomycin, hygromycin, etc.), or herbicide resistance (e.g.,glyphosate, etc.). Examples of selectable markers include, but are notlimited to, a neo gene (Potrykus et al., Mol. Gen. Genet. 199:183-188(1985)) which codes for kanamycin resistance and can be selected forusing kanamycin, G418, etc.; a bar gene which codes for bialaphosresistance; a mutant EPSP synthase gene (Hinchee et al., Bio/technology6:915-922 (1988)) which encodes glyphosate resistance; a nitrilase genewhich confers resistance to bromoxynil (Stalker et al., J. Biol. Chem.263:6310-6314 (1988)); a mutant acetolactate synthase gene (ALS) whichconfers imidazolinone or sulphonylurea resistance (European PatentApplication 154,204 (Sep. 11, 1985)); and a methotrexate resistant DHFRgene (Thillet et al., J. Biol. Chem. 263:12500-12508 (1988)).

A recombinant vector or construct of the present invention may alsoinclude a screenable marker. Screenable markers may be used to monitorexpression. Exemplary screenable markers include a β-glucuronidase oruidA gene (GUS) which encodes an enzyme for which various chromogenicsubstrates are known (Jefferson, Plant Mol. Biol, Rep. 5:387-405 (1987);Jefferson et al., EMBO J. 6:3901-3907 (1987)); an R-locus gene, whichencodes a product that regulates the production of anthocyanin pigments(red color) in plant tissues (Dellaporta et al., Stadler Symposium11:263-282 (1988)); a β-lactamase gene (Sutcliffe et al., Proc. Natl.Acad. Sci. (U.S.A.) 75:3737-3741 (1978)), a gene which encodes an enzymefor which various chromogenic substrates are known (e.g., PADAC, achromogenic cephalosporin); a luciferase gene (Ow et al., Science234:856-859 (1986)) a xylE gene (Zukowsky et al., Proc. Natl. Acad. Sci.(U.S.A.) 80:1101-1105 (1983)) which encodes a catechol dioxygenase thatcan convert chromogenic catechols; an α-amylase gene (Ikatu et al.,Bio/Technol. 8:241-242 (1990)); a tyrosinase gene (Katz et al., J. Gen.Microbiol. 129:2703-2714 (1983)) which encodes an enzyme capable ofoxidizing tyrosine to DOPA and dopaquinone which in turn condenses tomelanin; an α-galactosidase, which catalyzes a chromogenic α-galactosesubstrate.

In general it is preferred to introduce a functional recombinant DNA ata non-specific location in a plant genome. In special cases it may beuseful to insert a recombinant DNA construct by site-specificintegration. Several site-specific recombination systems exist which areknown to function implants include cre-10× as disclosed in U.S. Pat. No.4,959,317 and FLP-FRT as disclosed in U.S. Pat. No. 5,527,695.

In practice DNA is introduced into only a small percentage of targetcells in any one transformation experiment. Genes encoding selectablemarkers are used to provide an efficient system for identification ofthose cells that are stably transformed by receiving and integrating atransgenic DNA construct into their genomes. Preferred marker genesprovide selective markers that confer resistance to a selective agent,such as an antibiotic or herbicide. Any of the herbicides to whichplants of this invention may be resistant are useful agents forselective markers. Potentially transformed cells are exposed to theselective agent. In the population of surviving cells will be thosecells where, generally, the resistance-conferring gene is integrated andexpressed at sufficient levels to permit cell survival. Cells may betested further to confirm stable integration of the exogenous DNA.Commonly used selective marker genes include those conferring resistanceto antibiotics such as kanamycin (nptlI), hygromycin B (aph IV) andgentamycin (aac3 and aacC4) or resistance/tolerance to herbicides suchas glufosinate (bar or pat), glyphosate (EPSPS), and AMPA (phnO).Examples of such selectable markers are illustrated in U.S. Pat. Nos.5,550,318; 5,633,435; 5,780,708 and 6,118,047. Screenable markers whichprovide an ability to visually identify transformants can also beemployed, e.g., a gene expressing a colored or fluorescent protein suchas a luciferase or green fluorescent protein (GFP) or a gene expressinga beta-glucuronidase or uidA gene (GUS) for which various chromogenicsubstrates are known.

Preferred plant transformation vectors include those derived from a Tiplasmid of Agrobacterium tumefaciens (e.g. U.S. Pat. Nos. 4,536,475,4,693,977, 4,886,937, 5,501,967 and European Patent Application No.0122791). Agrobacterium rhizogenes plasmids (or “Ri”) are also usefuland known in the art. Other preferred plant transformation vectorsinclude those disclosed, e.g., by Herrera-Estrella (Nature 303:209-213,1983), Bevan (Nature 304:184-187,1983), Klee (Bio/Technol. 3:637-642,1985) and Eur. Pat Appl. No. EP 0120516.

Methods and compositions for transforming plants by introducing arecombinant DNA construct into a plant genome includes any of a numberof methods known in the art. One method for constructing transformedplants is microprojectile bombardment as illustrated in U.S. Pat. No.5,015,580 (soy), U.S. Pat. No. 5,550,318 (corn), U.S. Pat. No. 5,538,880(corn), U.S. Pat. No. 6,153,812 (wheat), U.S. Pat. No. 6,160,208 (corn),U.S. Pat. No. 6,288,312 (rice) and U.S. Pat. No. 6,399,861 (corn).Another method for constructing transformed plants isAgrobacterium-mediated transformation as illustrated in U.S. Pat. No.5,159,135 (cotton), U.S. Pat. No. 5,824,877 (soy), U.S. Pat. No.5,591,616 (corn) and U.S. Pat. No. 6,384,301 (soy).

The DNA constructs of the present invention may be introduced into thegenome of a desired plant host by a variety of conventionaltransformation techniques, which are well known to those skilled in theart. Suitable plant transformation vectors for the purpose ofAgrobacterium mediated transformation include those derived from a Tiplasmid of Agrobacterium tumefaciens, as well as those disclosed, e.g.,by Herrera-Estrella et al., Nature 303:209 (1983); Bevan, Nucleic AcidsRes. 12: 8711-8721 (1984); Klee et al., Bio-Technology 3(7): 637-642(1985); and EPO publication 120,516. In addition to Agrobacteriummediated plant transformation vectors, alternative methods can be usedto insert the DNA constructs of the present invention into plant cells.Such methods may involve, but are not limited to, for example, the useof liposomes, electroporation, chemicals that increase free DNA uptake,free DNA delivery via microprojectile bombardment, and transformationusing viruses or pollen.

Any of the isolated nucleic acid molecules of the present invention maybe introduced into a plant cell in a permanent or transient manner incombination with other genetic elements such as promoters, introns,enhancers, and untranslated leader sequences, etc. Any of the nucleicacid molecules encoding a coleopteran species RNA or an RNA from apiercing and sucking insect species, or preferably a D. v. virgifera RNAor a Lygus hesperus RNA, may be fabricated and introduced into a plantcell in a manner that allows for production of the dsRNA moleculeswithin the plant cell, providing an insecticidal amount of one or moreparticular dsRNA's in the diet of a target insect pest.

The term “transgenic plant cell” or “transgenic plant” refers to a plantcell or a plant that contains an exogenous nucleic acid, which can bederived from a lygus bug or other sucking and piercing insect, or from adifferent insect species or any other non-insect species. The transgenicplants are also meant to comprise progeny (decedent, offspring, etc.) ofany generation of such a transgenic plant or a seed of any generation ofall such transgenic plants wherein said progeny or seed comprises a DNAsequence encoding the RNA, sRNA, dsRNA, siRNA, or fragment thereof ofthe present invention is also an important aspect of the invention.

A transgenic plant formed using Agrobacterium transformation methodstypically contains a single simple recombinant DNA sequence insertedinto one chromosome and is referred to as a transgenic event. Suchtransgenic plants can be referred to as being heterozygous for theinserted exogenous sequence. A transgenic plant homozygous with respectto a transgene can be obtained by sexually mating (selfing) anindependent segregant transgenic plant that contains a single exogenousgene sequence to itself, for example an F0 plant, to produce F1 seed.One fourth of the F1 seed produced will be heterozygous with respect tothe transgene. Germinating F1 seed results in plants that can be testedfor heterozygosity, typically using a SNP assay or a thermalamplification assay that allows for the distinction betweenheterozygotes and homozygotes (i.e., a zygosity assay). Crossing aheterozygous plant with itself or another heterozygous plant results inonly heterozygous progeny.

In addition to direct transformation of a plant with a recombinant DNAconstruct, transgenic plants can be prepared by crossing a first planthaving a recombinant DNA construct with a second plant lacking theconstruct. For example, recombinant DNA for gene suppression can beintroduced into first plant line that is amenable to transformation toproduce a transgenic plant which can be crossed with a second plant lineto introgress the recombinant DNA for gene suppression into the secondplant line.

Transgenic plants, that can be generated by practice of the presentinvention, include but are not limited to alfalfa, aneth, apple,apricot, artichoke, arugula, asparagus, avocado, banana, barley, beans,beet, blackberry, blueberry, broccoli, brussel sprouts, cabbage, canola,cantaloupe, carrot, cassaya, cauliflower, celery, cherry, cilantro,citrus, clementine, coffee, corn, cotton, cucumber, Douglas fir,eggplant, endive, escarole, eucalyptus, fennel, figs, gourd, grape,grapefruit, honey dew, jicama, kiwifruit, lettuce, leeks, lemon, lime,Loblolly pine, mango, melon, mushroom, nut, oat, okra, onion, orange, anornamental plant, papaya, parsley, pea, peach, peanut, pear, pepper,persimmon, pine, pineapple, plantain, plum, pomegranate, poplar, potato,pumpkin, quince, radiata pine, radicchio, radish, raspberry, rice, rye,sorghum, Southern pine, soybean, spinach, squash, strawberry, sugarbeet,sugarcane, sunflower, sweet potato, sweetgum, tangerine, tea, tobacco,tomato, turf, a vine, watermelon, wheat, yams, and zucchini.

The present invention can be, in practice, combined with other insectcontrol traits in a plant to achieve desired traits for enhanced controlof insect infestation. Combining insect control traits that employdistinct modes-of-action can provide insect-protected transgenic plantswith superior durability over plants harboring a single insect controltrait because of the reduced probability that resistance will develop inthe field.

The mechanism of insecticidal activity of B. thuringiensis crystalproteins has been studied extensively in the past decade. It has beenshown that the crystal proteins are toxic to the larval form of theinsect only after ingestion of the protein. In lepidopteran larvae, analkaline pH and proteolytic enzymes in the insect mid-gut solubilize theproteins, thereby allowing the release of components that are toxic tothe insect. These toxic components disrupt the mid-gut cells, cause theinsect to cease feeding, and, eventually, bring about insect death. Forthis reason, B. thuringiensis toxins have proven themselves to beeffective and environmentally safe insecticides in dealing with variousinsect pests. Coleopteran and hemipteran insects, and likely dipteran,lygus and other piercing and sucking insects exhibit a gut pH that isslightly acidic, and so the Bt toxins that are effective againstlepidopteran larvae are ineffective against these pests. The slightlyacidic pH of the gut of these insects is also believed to be morehospitable to the compositions of the present invention, and withoutintending to be limited to a particular theory, it is likely that thealkaline pH of the gut of lepidopteran larvae is the reason that priorattempts to exhibit dsRNA efficacy has failed (Fire et al. U.S. Pat. No.6,506,559; Mesa et al. Patent Publication No. U.S. 2003/0150017 A1;Rajagopal et al. 2002, J. Biol. Chem. 277:46849-46851; Tabara et al.,1998, Science 282:430-431). It is believed therefore that the dsRNAmethods disclosed herein should be preferentially used in compositionsand in plants to control coleopteran, dipteran, hemipteran, lygus, andpiercing and sucking insects. The methods and compositions set forthherein are particularly useful for targeting genes for suppression ininsects exhibiting a gut pH of from about 4.5 to about 9.5, or fromabout 5.0 to about 9.0, or from about 5.5 to about 8.5, or from about6.0 to about 8.0, or from about 6.5 to about 7.7, or from about 6.8 toabout 7.6, or about 7.0. However, insects and other pest species thatexhibit a gut pH of from about 7.5 to about 11.5, or from about 8.0 toabout 11.0, or from about 9.0 to about 10.0, such as lepidopteran insectlarvae, are also intended to be within the scope of the presentinvention. This is particularly true when a dsRNA specific forinhibiting a gene in a lepidopteran larvae is provided in the diet ofthe larvae along with one or more Bt proteins, that, with respect to theBt protein would ordinarily be toxic to that lepidopteran larvae whenprovided at or above a threshold level. The presence of one or more Bttoxins toxic to the same insect species would effectively reduce the gutpH, providing a stable environment for the double stranded RNA moleculesto exert their effects in suppressing a target gene in the insect pest.

It would be useful to combine one or more stabilized dsRNA constructsproducing dsRNA molecules of the present invention in the diet of atarget insect pest along with one or more insecticidal proteins, suchthat the dsRNA and the insecticidal protein are toxic to the same insectpest. The insecticidal protein could be derived from B. thuringiensisbut also from other organisms known in the art to produce insecticidalproteins such as bacterial symbionts of entomopathogenic nematodes (e.g.Photorhabdus sp., Xenorhabdus sp.), Serratia entomophila and relatedSerratia sp., B. sphaericus, B. cereus, B. laterosporus, B. popilliae,Clostridium bifernentans, or other spore-forming gram-positive bacteriathat exhibit insecticidal properties. Likewise, it is envisioned thattwo or more different stabilized dsRNA constructs producing dsRNAmolecules of the present invention could be provided together within asingle plant to ensure durability of the insect control phenotype. ThesedsRNA molecules could target the same gene for silencing or,alternatively, target different genes for silencing. Two or moredifferent dsRNA's can be combined together in the same plant, each dsRNAbeing toxic to a different insect pest, neither of the dsRNA's beingtoxic to the same insect species.

It is anticipated that the combination of certain stabilized dsRNAconstructs with one or more insect control protein genes will result insynergies that enhance the insect control phenotype of a transgenicplant. Insect bioassays employing artificial diet- or whole plant tissuecan be used to define dose-responses for larval mortality or growthinhibition using both dsRNAs and insect control proteins. One skilled inthe art can test mixtures of dsRNA molecules and insect control proteinsin bioassay to identify combinations of actives that are synergistic anddesirable for deployment in insect-protected plants. It is anticipatedthat synergies will exist between certain dsRNAs and between certaindsRNAs and certain insect control proteins.

It is also anticipated that combinations of dsRNA's will revealunexpected toxicity towards certain insect pests. Rajagopal et al (2002)reported that feeding dsRNAs to larvae of the lepidopteran pest S.litura was ineffective in silencing a gene encoding a midgutaminopeptidase. It is worth noting that the alkaline pH environment ofthe typical lepidopteran midgut may be a hostile environment for dsRNAssince the denaturation of RNA duplexes at alkaline pH would be expectedto lead to rapid degradation. Significantly, the pH regulation of thelepidopteran midgut, maintained by an electrogenic K+-pump, is disruptedby ion channels. Pores formed by B. thuringiensis toxin proteinsinserted into the midgut epithelial membrane, result in a neutralizationof the midgut pH. Accordingly, B. thuringiensis toxin proteins that areonly capable of forming transient ion channels in the lepidopteranmidgut epithelial membrane without causing mortality may be sufficientto reduce the midgut pH to levels more conducive for the uptake ofdsRNAs by midgut epithelial cells. As one example, it is known that theCry1Ac protein is not an effective toxin against the beet armyworm,Spodoptera exigua. Nevertheless, transient reductions in midgut pHcaused by the Cry1Ac protein could serve to stabilize co-ingested dsRNAsand render them effective in silencing S. exigua target genes, therebyproviding an unexpected means of controlling this insect pest. Thiseffect could be observed with any protein, insecticidal or not, thatdisrupts the ion regulation of lepidopteran insect midgut cells, and mayalso be effective in coleopteran, dipteran, hemipteran, lygus bug andother piercing and sucking insect species, and the like.

Some insecticidal proteins from B. thuringiensis, such as the Cytproteins, may cause transient openings in the midgut epithelial membraneof sensitive insect larvae due to the formation of structured pores orto the general detergent-like activity of the protein. Such openingscould facilitate the passage of dsRNA molecules into midgut epithelialcells even at protein concentrations that are sub-optimal for causingmortality. It is anticipated that any protein, insecticidal or not, thatcauses transient openings in the epithelial membranes of insects couldfacilitate the passage of dsRNA molecules into insect cells and promotegene silencing.

The nucleotide sequences provided as set forth in SEQ ID NO:4 throughSEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184 or fragmentsthereof, or complements thereof, can be “provided” in a variety ofmediums to facilitate use. Such a medium can also provide a subsetthereof in a form that allows a skilled artisan to examine thesequences.

In one application of this embodiment, a nucleotide sequence of thepresent invention can be recorded on computer readable media. As usedherein, “computer readable media” refers to any tangible medium ofexpression that can be read and accessed directly by a computer. Suchmedia include, but are not limited to: magnetic storage media, such asfloppy discs, hard disc, storage medium, and magnetic tape: opticalstorage media such as CD-ROM; electrical storage media such as RAM andROM; optical character recognition formatted computer files, and hybridsof these categories such as magnetic/optical storage media. A skilledartisan can readily appreciate that any of the presently known computerreadable mediums can be used to create a manufacture comprising computerreadable medium having recorded thereon a nucleotide sequence of thepresent invention.

As used herein, “recorded” refers to a process for storing informationon computer readable medium. A skilled artisan can readily adopt any ofthe presently known methods for recording information on computerreadable medium to generate media comprising the nucleotide sequenceinformation of the present invention. A variety of data storagestructures are available to a skilled artisan for creating a computerreadable medium having recorded thereon a nucleotide sequence of thepresent invention. The choice of the data storage structure willgenerally be based on the means chosen to access the stored information.In addition, a variety of data processor programs and formats can beused to store the nucleotide sequence information of the presentinvention on computer readable medium. The sequence information can berepresented in a word processing text file, formatted incommercially-available software such as WordPerfect and Microsoft Word,or represented in the form of an ASCII text file, stored in a databaseapplication, such as DB2, Sybase, Oracle, or the like. The skilledartisan can readily adapt any number of data processor structuringformats (e.g. text file or database) in order to obtain computerreadable medium having recorded thereon the nucleotide sequenceinformation of the present invention.

Computer software is publicly available which allows a skilled artisanto access sequence information provided in a computer readable medium.Software that implements the BLAST (Altschul et al., J. Mol. Biol. 215:403-410 (1990)) and BLAZE (Brutlag, et al., Comp. Chem. 17: 203-207(1993)) search algorithms on a Sybase system can be used to identifyopen reading frames (ORFs) within sequences such as the EST's that areprovided herein and that contain homology to ORFs or proteins from otherorganisms. Such ORFs are protein-encoding fragments within the sequencesof the present invention and are useful in producing commerciallyimportant proteins such as enzymes used in amino acid biosynthesis,metabolism, transcription, translation, RNA processing, nucleic acid anda protein degradation, protein modification, and DNA replication,restriction, modification, recombination, and repair.

The present invention further provides systems, particularlycomputer-based systems, which contain the sequence information describedherein. Such systems are designed to identify commercially importantfragments of the nucleic acid molecule of the present invention. As usedherein, “a computer-based system” refers to the hardware means, softwaremeans, and data storage means used to analyze the nucleotide sequenceinformation of the present invention. The minimum hardware means of thecomputer-based systems of the present invention comprises a centralprocessing unit (CPU), input means, output means, and data storagemeans. A skilled artisan can readily appreciate that any one of thecurrently available computer-based system are suitable for use in thepresent invention.

The most preferred sequence length of a target sequence is from about 10to about 100 amino acids or from about 23 to about 300 nucleotideresidues.

As used herein, “a target structural motif,” or “target motif,” refersto any rationally selected sequence or combination of sequences in whichthe sequences or sequence(s) are chosen based on a three-dimensionalconfiguration that is formed upon the folding of the target motif. Thereare a variety of target motifs known in the art. Protein target motifsinclude, but are not limited to, enzymatic active sites and signalsequences. Nucleic acid target motifs include, but are not limited to,promoter sequences, cis elements, hairpin structures and inducibleexpression elements (protein binding sequences).

EXAMPLES

The inventors herein have identified a means for controllinginvertebrate pest infestation by providing a double stranded ribonucleicacid molecule in the diet of the pest. Surprisingly, the inventors havediscovered that a double stranded ribonucleic acid molecule functionsupon ingestion by the pest to inhibit a biological function in the pest,resulting in one or more of the following attributes: reduction infeeding by the pest, reduction in viability of the pest, death of thepest, inhibition of differentiation and development of the pest, absenceof or reduced capacity for sexual reproduction by the pest, muscleformation, juvenile hormone formation, juvenile hormone regulation, ionregulation and transport, maintenance of cell membrane potential, aminoacid biosynthesis, amino acid degradation, sperm formation, pheromonesynthesis, pheromone sensing, antennae formation, wing formation, legformation, development and differentiation, egg formation, larvalmaturation, digestive enzyme formation, haemolymph synthesis, haemolymphmaintenance, neurotransmission, cell division, energy metabolism,respiration, apoptosis, and any component of a eukaryotic cells'cytoskeletal structure, such as, for example, actins and tubulins. Anyone or any combination of these attributes can result in an effectiveinhibition of pest infestation, and in the case of a plant pest,inhibition of plant infestation. For example, when used as a dietcomposition containing a pest inhibitory sufficient amount of one ormore double stranded ribonucleic acid molecules provided topically to aplant, as a seed treatment, as a soil application around a plant, orwhen produced by a plant from a recombinant DNA molecule present withinthe cells of a plant, plant pest infestation is unexpectedlydramatically reduced. The Examples set forth herein below areillustrative of the invention when applied to a single pest. However,the skilled artisan will recognize that the methods, formulae, and ideaspresented in the Examples are not intended to be limiting, and areapplicable to all invertebrate pest species that can consume foodsources that can be formulated to contain a sufficient amount of a pestinhibitory agent consisting at least of one or more double stranded RNAmolecules exemplified herein intended to suppress some essential featureabout or function within the pest.

Example 1

This example illustrates the identification of nucleotide sequencesthat, when provided in the double stranded RNA form in the diet of alygus species insect pest, are useful for controlling a lygus speciesinsect pest.

Lygus species, and in particular Lygus hesperus, are typical of a classof pests that infest crop plants and ornamentals and globally causesevere commercially significant levels of damage on an annual basis.This class of pests effect their damage by piercing the defenses of aplant, plant tissue, or plant cell and subsequently extract nutritionalvalue from the plants. Nutritional value is captured by the pest usingthis means of attack by one of two or three modes of action. One meansis to puncture or penetrate into individual cells and suck out thejuices of those cells. Another means is to penetrate into the xylem orphloem vesicles of the plant or plant tissues and allow the turgorpressure within the plant to extrude nutritionally rich xylem or phloemfluids through the pests' proboscis and on through the gut of the pest.Still, a third means is to inject a mixture of digestive enzymes beneaththe surface of the plant or plant tissue, resulting in the degradationof physical cellular structures and the release of intracellular fluidsinto the interstitial spaces between the attacked cells, at which pointthe plant cellular fluids are extracted through the pests' proboscis.Other piercing and sucking pests are known in the art and infest avariety of species. Such pests include but are not limited to fleas,lice, ticks, mites, biting flies, and mosquitoes. It would be useful toidentify a means for controlling such pest infestation.

Lygus hesperus cDNA libraries were prepared essentially as describedabove in Example 1 for the production of corn rootworm cDNA libraries.Lygus cDNA libraries were constructed from whole lygus bugs at differentdevelopmental stages and at different times within each developmentalstage in order to maximize the number of different EST sequences fromthe lygus species. Libraries LIB5443 and LIB5461 were preparedrespectively from RNA purified from nymph (approximately 1 gram) andadult (approximately 2.6 grams) lygus bugs. Briefly, insects werequickly frozen in liquid nitrogen. The frozen insects were reduced to afine powder by grinding in a mortar and pestle. RNA was extracted usingTRIzol® reagent (Invitrogen) following the manufacturer's instructions.Poly A+ RNA was isolated from the total RNA prep using Dynabeads OligodT (Dynal Inc., NY). A cDNA library was made from the Poly A+ RNA usingthe SuperScript™ Plasmid System (Invitrogen). The cDNA was sizefractionated using chromatography, and fractions were collected andligated into the pSPORTI vector in between the SalI and NotI restrictionsites and transformed into E. coli DH10B electro-competent cells byelectroporation. LIB5443 yielded a total titer of about 620,000 colonyforming units. LIB5461 yielded a total titer of about 1.63×10⁶ colonyforming units. Colonies from the Lygus hesperus cDNA libraries LIB5444and LIB5462 were amplified individually in a high viscosity medium.Approximately 600,000 colony-forming units from LIB5444 and LIB5462 weremixed on a stir plate separately in 500 ml LB medium containing 0.3%SeaPrep agarose® and 50 mg/l carbenecillin at 37° C. and then rapidlycooled in a water/ice bath for 1 hour allowing uniform suspension of thebacterial colonies. The inoculated libraries were then grown at 30° C.for 42 hours. After incubation, the cells were mixed for 5 minutes on astir plate. The medium was then transferred to two 250 ml centrifugebottles. The bacterial cells were pelleted at 10,000×g for 10 minutes.The medium was removed from the bottles and the cells were resuspendedin a total of 20 ml of LB medium with 50 mg/l carbenecillin. Dimethylsulfoxide was added to 10% to preserve the cells in freezing. Bothlibraries were amplified to a final titer of 10⁸ colony-forming unitsper milliliter. Samples of the Lygus hesperus cDNA libraries LIB 5443and LIB5461 were combined and adjusted to a DNA concentration of about1.25 micrograms per microliter in sterile distilled and deionized waterand aliquoted into twenty five cryovials, each cryovial containing about8.75 micrograms of DNA. These samples were deposited by theapplicant(s)/inventors with the American Type Culture Collection (ATCC)located at 10801 University Boulevard, Manassas, Va., USA ZIP 20110-2209on Jun. 10, 2004 and referred to as LIB5443/61. The ATCC provided theApplicant with a deposit receipt, assigning the ATCC Deposit AccessionNo.PTA-6073. Inserted cDNA sequence information was obtained from thelygus plasmid libraries.

Libraries LIB5497 and LIB5503 were prepared respectively from RNApurified from nymph (approximately 1 gram) and adult (approximately 1gram) lygus bugs. Briefly, insects were quickly frozen in liquidnitrogen. The frozen insects were reduced to a fine powder by grindingin a mortar and pestle. RNA was extracted using TRizol® reagent(Invitrogen) following the manufacturer's instructions. Poly A+ RNA wasisolated from the total RNA prep using Dynabeads Oligo dT (Dynal Inc.,NY). A high molecular weight cDNA library was made from 20 micrograms ofPoly A+ RNA using the SuperScript™ Plasmid System (Invitrogen). The cDNAwas size fractionated on a 1% agarose gel in TAE, and cDNA between therange of 1 Kb to 10 Kb was collected and ligated into the pSPORTI vectorin between the SalI and NotI restriction sites and transformed into E.coli DH10B electro-competent cells by electroporation. LIB5497 yielded atotal titer of about 600,000 colony forming units. LIB5503 yielded atotal titer of about 366,000 colony forming units. Colonies from theLygus hesperus cDNA libraries LIB5497 and LIB5503 were amplifiedindividually in a high viscosity medium. Approximately 200,000colony-forming units from LIB5497 and LIB5503 were mixed on a stir plateseparately in 500 ml LB medium containing 0.3% SeaPrep agarose® and 50mg/l carbenecillin at 37° C. and then rapidly cooled in a water/ice bathfor 1 hour allowing uniform suspension of the bacterial colonies. Theinoculated libraries were then grown at 30° C. for 42 hours. Afterincubation, the cells were mixed for 5 minutes on a stir plate. Themedium was then transferred to two 250 ml centrifuge bottles. Thebacterial cells were pelleted at 10,000×g for 10 minutes. The medium wasremoved from the bottles and the cells were resuspended in a total of 20ml of LB medium with 50 mg/l carbenecillin. Dimethyl sulfoxide was addedto 10% to preserve the cells in freezing. Both libraries were amplifiedto a final titer of 10⁸ colony-forming units per milliliter.

The first pass sequences of the lygus libraries together produced about11,461 individual EST sequences consisting of approximately 9.05×10⁶nucleotide residues. The average length of an EST sequence was about 790nucleotide residues. These EST sequences were subjected tobioinformatics algorithms that resulted in the assembly of somecontiguous sequences referred to as UNIGENE's, and some individual ESTsequences that could not be compiled by overlap identity with other ESTsequences, referred to herein as singletons. The lygus libraries weresequenced much deeper and an additional individual EST sequences.

All the EST sequences obtained from all six libraries, i.e., LIB5433,LIB5438, LIB5443, LIB5461, LIB5497 and LIB5503, are assembled intoUnigene sequences. Each nucleotide sequence as set forth in the SequenceListing was analyzed to identify the presence of open reading frames.Amino acid sequence information deduced from open reading frames wascompared to known amino acid sequence information available in publicdatabases in order to deduce the extent of amino acid sequence identityor similarity to those known amino acid sequences. Biological function,if any, associated with known amino acid sequences in public databaseswas annotated to the amino acid sequences deduced from the cDNA librarynucleotide sequence information. Annotations provided information thatwas suggestive of the function of a protein that may be expressed from aparticular gene that gave rise to a particular cDNA sequence, but wasnot outcome determinative. Based on the suggestive annotationinformation, certain cDNA sequences were characterized as those thatencoded a protein that was likely involved in some biological functionwithin lygus cells that was either essential to life, or that wasnecessary for ensuring health and vitality to a cell, or were likely tobe involved in cellular integrity, cell maintenance, reproductivecapacity, and the like. The Unigene sequences assembled are as set forthin the Sequence Listing from SEQ ID NO:4 through SEQ ID NO:14 and SEQ IDNO:180 through SEQ ID NO:184.

Several cDNA sequences were selected from those cDNA sequences likelyencoding proteins, the inhibition of which was likely to cause morbidityor mortality to lygus, or to other invertebrate species cells. Thesesequences were then used in the construction of double stranded RNAmolecules for incorporation into lygus diet.

Thermal amplification primer pairs were designed based on the cDNAsequences reported in the lygus cDNA library. Primer pairs wereconstructed either as a pair of nucleotide sequences, each member of aprimer pair exhibiting perfect complementarity either to a sense or toan antisense sequence. Some primer pair sequences were constructed sothat each member of the pair exhibited a sequence containing a T7 phageRNA polymerase promoter at it's 5′ end as set forth, for example, in SEQID NO:16 from nucleotide position 1 through nucleotide position 23.Preferably a higher fidelity first amplification reaction was carriedout using a first primer pair lacking a T7 promoter to generate a firstamplicon using lygus genomic DNA as template. Preferably a cDNA or amRNA sequence is used as the template for the synthesis of a dsRNAmolecule for use in the present invention because eukaryotic genomesequences are recognized in the art to contain sequences that are notpresent within the mature RNA molecule. A sample of the first amplicongenerated from the higher fidelity first amplification reaction was thenused as template in a second thermal amplification reaction with asecond primer pair containing the T7 promoter sequence to produce asecond amplicon that contained a T7 promoter at or embedded within the5′ end of each strand of the second amplicon. The complete nucleotidesequence of the second amplicon was obtained in both directions andcompared to the nucleotide sequence as reported for the cDNA, anddiscrepancies between the two sequences, if any, were noted. Generally,sequences prepared using genome DNA as template were inconsistent withfurther use as dsRNA molecules for use in achieving significant levelsof suppression because of variations within the genome sequences thatwere not present within the mRNA or cDNA sequence.

The following EST sequences as set forth in the Sequence Listing andderived from lygus cDNA libraries are identified for use in suppressionof corresponding mRNA sequences expressed within lygus bugs using thedouble stranded RNA mediated methods described herein. SEQ ID NO:4through SEQ ID NO:14 and SEQ ID NO:180 through SEQ ID NO:184 as setforth in the Sequence Listing are useful in constructing double strandedRNA sequences that can be provided in the diet of a lygus bug or arelated species to suppress a target gene expressing a mRNA sequencethat exhibits from about 85 to about 99% or greater nucleotide sequenceidentity to the double stranded RNA sequence provided. Specifically, SEQID NO:11 (encoding a protein exhibiting similarity to a V-ATPaseprotein), SEQ ID NO:8 (encoding a protein exhibiting similarity to aubiquitin protein), SEQ ID NO:10 (encoding a protein exhibitingsimilarity to a polyglacturonase protein), SEQ ID NO:9 (encoding aprotein exhibiting similarity to a pectinase protein), SEQ ID NO:14(encoding a protein exhibiting similarity to a GABA neurotransmittertransporter protein), SEQ ID NO:6 (encoding a protein exhibitingsimilarity to a EFI alpha protein), SEQ ID NO:5 and SEQ ID NO:12(encoding proteins exhibiting similarity to a cytochrome P-450mono-oxygenase protein), SEQ ID NO:7 (encoding a protein exhibitingsimilarity to a cuticle protein precursor protein), SEQ ID NO:13(encoding a protein exhibiting similarity to a CHD3 protein), and SEQ IDNO:4 (encoding a protein exhibiting similarity to a 20S proteasomeprotein). dsRNA sequences are provided in the diet in bioassays to lygusbugs. Lygus bugs consume the dsRNA sequences with the diet and the dsRNAsequences function to inhibit one or more genes in the lygus bugs,resulting in death, inhibition of growth, cessation of feeding, orinability to reproduce. dsRNA sequences identified in this way are thenprepared for incorporation into a plant genome and a transgenic plantexpressing one or more double stranded RNA molecules is prepared that isprovided in the diet of a lygus bug. Lygus bugs are infested onto thetransgenic plant. The lygus bugs feed upon the transgenic plantexpressing lygus bug inhibitory amounts of said dsRNA and the lygus buginfestation is inhibited.

Example 2

This example illustrates the identification of nucleotide sequencesthat, when provided in the form of double stranded RNA molecules in thediet of a corn rootworm, are useful for controlling corn rootworms.

Corn rootworm cDNA libraries (LIB149, LIB 150, LIB3027, LIB3373) wereconstructed from whole larvae and from dissected midgut sections, andnucleotide sequence information was obtained (see Andersen et al., U.S.patent application Ser. No. 10/205,189 filed Jul. 24, 2002, incorporatedherein specifically by reference in its entirety). In addition, cDNAlibraries were constructed from whole larvae at different developmentalstages and at different times within each developmental stage in orderto maximize the number of different EST sequences from the Diabroticaspecies. Libraries LIB5444 and LIB5462 were constructed respectivelyfrom mRNA pools obtained from first (1 gram) and third (2.9 grams)instar Western Corn Rootworm larvae. Harvested insects were rapidlyfrozen by insertion into liquid nitrogen. The insects were ground in amortar and pestle maintained at or below −20C by chilling on dry iceand/or with the addition of liquid nitrogen to the mortar until thetissue was ground into a fine powder. RNA was extracted using TRIzol®reagent (Invitrogen) according to the manufacturer's instructions. PolyA+ RNA was isolated from the total RNA prep using Dynabeads Oligo dT(Dynal Inc., NY) following the manufacturer's instructions. A cDNAlibrary was constructed from the Poly A+ RNA using the SuperScript™Plasmid System (Invitrogen). cDNA was size fractionated usingchromatography. The fourth and fifth fractions were collected andligated into the pSPORTI vector (Life Technologies Inc., GaithersburgMd.) between the SalI and NotI restriction endonucleases recognitionsites, and transformed into E. coli DH10B electro-competent cells byelectroporation. The first instar larvae library yielded about 420,000colony forming units. The third instar larvae library yielded about2.78×10⁶ colony forming units. Colonies from LIB149, LIB150 were washedfrom the plates, mixed to uniformity by vortexing briefly, and pooledinto Tris-EDTA buffer. Half of the wash was brought to 10% glycerol,aliquoted into cryovials, and stored at −70C. The other half was used toproduce plasmid DNA using a Quiagen midi-prep purification column, orits equivalent. Purified plasmid DNA was aliquoted to microcentrifugetubes and stored at −20C.

Colonies from the Diabrotica virgifera cDNA libraries LIB5444 andLIB5462 were amplified individually in a high viscosity medium.Approximately 200,000 colony-forming units from LIB5444 and 600,000colony-forming units from LIB5462 were mixed on a stir plate separatelyin 500 ml LB medium containing 0.3% SeaPrep agarose® and 50 mg/lcarbenecillin at 37° C. and then rapidly cooled in a water/ice bath for1 hour allowing uniform suspension of the bacterial colonies. Theinoculated libraries were then grown at 30° C. for 42 hours. Afterincubation, the cells were mixed for 5 minutes on a stir plate. Themedium was then transferred to two 250 ml centrifuge bottles. Thebacterial cells were pelleted at 10,000×g for 10 minutes. The medium wasremoved from the bottles and the cells were resuspended in a total of 20ml of LB medium with 50 mg/l carbenecillin. Dimethyl sulfoxide was addedto 10% to preserve the cells in freezing. Both libraries were amplifiedto a final titer of 10⁸ colony-forming units per milliliter. Samples ofthe Diabrotica virgifera cDNA libraries LIB5444 and LIB5462 werecombined and adjusted to a DNA concentration of about 1.25 microgramsper microliter in sterile distilled and deionized water and aliquotedinto twenty five cryovials, each cryovial containing about 8.75micrograms of DNA. These samples were deposited by theapplicant(s)/inventors with the American Type Culture Collection (ATCC)located at 10801 University Boulevard, Manassas, Va., USA ZIP 20110-2209on Jun. 10, 2004 and referred to as LIB5444/62. The ATCC provided theApplicant with a deposit receipt, assigning the ATCC Deposit AccessionNo.PTA-6072.

Corn rootworm high molecular weight cDNA libraries, i.e., LIB5496 andLIB5498, were prepared essentially as described above for the productionof corn rootworm cDNA libraries. Libraries LIB5496 and LIB5498 wereconstructed respectively from mRNA pools obtained from first (1 gram)and second and third (1 gram) instar Western Corn Rootworm larvae.Briefly, insects were quickly frozen in liquid nitrogen. The frozeninsects were reduced to a fine powder by grinding in a mortar andpestle. RNA was extracted using TRIzol® reagent (Invitrogen) followingthe manufacturer's instructions. Poly A+ RNA was isolated from the totalRNA prep using Dynabeads Oligo dT (Dynal Inc., NY). A high molecularweight cDNA library was made from 20 micrograms of Poly A+ RNA using theSuperScript™ Plasmid System (Invitrogen). The cDNA was size fractionatedon a 1% agarose gel in TAE, and cDNA between the range of 1 Kb to 10 Kbwas collected and ligated into the pSPORTI vector in between the SalIand NotI restriction sites and transformed into E. coli DH10Belectro-competent cells by electroporation. LIB5496 yielded a totaltiter of about 3.5×10⁶ colony forming units. LIB5498 yielded a totaltiter of about 1.0×10⁶ colony forming units. Colonies from the cornrootworm high molecular weight cDNA libraries LIB5496 and LIB5498 wereamplified individually in a high viscosity medium. Approximately 600,000colony-forming units from LIB5496 and LIB35498 were mixed on a stirplate separately in 500 ml LB medium containing 0.3% SeaPrep agarose®and 50 mg/l carbenecillin at 37° C. and then rapidly cooled in awater/ice bath for 1 hour allowing uniform suspension of the bacterialcolonies. The libraries were then grown at 30° C. for 42 hours. Afterincubation, the cells were mixed for 5 minutes on a stir plate. Themedium was then transferred to two 250 mL centrifuge bottles. Thebacterial cells were pelleted at 10,000×g for 10 minutes. The medium wasremoved from the bottles and the cells were resuspended in a total of 20mL of LB medium with 50 mg/L carbenecillin. Dimethyl sulfoxide was addedto 10% to preserve the cells in freezing. Both libraries were amplifiedto a final titer of 10⁸ colony-forming units per milliliter. InsertedcDNA sequence information was obtained from the corn rootworm speciesspecific plasmid libraries.

The Andersen et al. rootworm libraries together with additionalsequences from the libraries LIB5444 and LIB5462 initially producedabout 18,415 individual EST sequences consisting of approximately1.0×10⁷ nucleotide residues. The average length of an EST sequence wasabout 586 nucleotide residues. These EST sequences were subjected tobioinformatics algorithms that resulted in the assembly of contigsequences referred to herein as UNIGENE sequences, and individual ESTsequences that could not be compiled by overlap identity with other ESTsequences, referred to herein as singletons. The LIB5444 and LIB5462libraries were then sequenced much deeper, resulting in additionalindividual EST sequences. EST sequences isolated from CRW cDNA librarieswere assembled, where possible, into UNIGENE sets. A UNIGENE is agene-oriented cluster formed from the overlap of individual ESTsequences within regions of sequence identity to form a larger sequence.Pontius et al., Nucl Acids Res 31:28-33 (2003). Each nucleotide sequenceas set forth in the sequence listing was analyzed to identify thepresence of open reading frames. Amino acid sequence information deducedfrom open reading frames was compared to known amino acid sequenceinformation available in public databases in order to deduce the extentof amino acid sequence identity or similarity to those known amino acidsequences. Biological function, if any, associated with known amino acidsequences in public databases was annotated to the amino acid sequencesdeduced from the cDNA library nucleotide sequence information.Annotations provided information that was suggestive of the function ofa protein that may be expressed from a particular gene that gave rise toa particular cDNA sequence, but was not outcome determinative. Based onthe suggestive annotation information, certain cDNA sequences werecharacterized as those that encoded a protein that was likely involvedin some biological function within corn rootworm cells that was eitheressential to life, or that was necessary for ensuring health andvitality to a cell, or were likely to be involved in cellular integrity,cell maintenance, reproductive capacity, and the like.

Several cDNA sequences were selected from this subset of cDNA sequenceslikely encoding proteins, the inhibition of which was likely to causemorbidity or mortality to CRW or to other invertebrate species cells.These sequences were then used in the construction of double strandedRNA molecules for incorporation into CRW diet.

Thermal amplification primer pairs were designed based on the cDNAsequences reported in the CRW cDNA library. Primer pairs wereconstructed either as a pair of nucleotide sequences, each member of aprimer pair exhibiting perfect complementarity either to a sense or toan antisense sequence. Some primer pair sequences were constructed sothat each member of the pair exhibited a sequence containing a T7 phageRNA polymerase promoter at it's 5′ end as set forth, for example, in SEQID NO:16 from nucleotide position 1 through nucleotide position 23.Preferably a higher fidelity first amplification reaction was carriedout using a first primer pair lacking a T7 promoter to generate a firstamplicon using CRW genomic DNA as template. Preferably a cDNA or a mRNAsequence is used as the template for the synthesis of a dsRNA moleculefor use in the present invention because eukaryotic genome sequences arerecognized in the art to contain sequences that are not present withinthe mature RNA molecule. A sample of the first amplicon generated fromthe higher fidelity first amplification reaction was then used astemplate in a second thermal amplification reaction with a second primerpair containing the T7 promoter sequence to produce a second ampliconthat contained a T7 promoter at or embedded within the 5′ end of eachstrand of the second amplicon. The complete nucleotide sequence of thesecond amplicon was obtained in both directions and compared to thenucleotide sequence as reported for the cDNA, and discrepancies betweenthe two sequences, if any, were noted. Generally, sequences preparedusing genome DNA as template were inconsistent with further use as dsRNAmolecules for use in achieving significant levels of suppression becauseof variations within the genome sequences that were not present withinthe mRNA or cDNA sequence.

An in vitro transcription reaction typically contained from about 1 toabout 2 micrograms of linearized DNA template, T7 polymerase reactionbuffer from a 10× concentrate, ribonucleotides ATP, CTP, GTP, and UTP ata final concentration of from between 50 and 100 mM each, and 1 unit ofT7 RNA polymerase enzyme. The RNA polymerase reaction was incubated atabout 37C, depending on the optimal temperature of the RNA polymeraseused according to the manufacturers' instructions, for a period of timeranging from several minutes to several hours. Generally, reactions werecarried out for from about 2 to about 6 hours for transcription oftemplate sequences up to about 400 nucleotides in length, and for up to20 hours for transcription of template sequences greater than about 400nucleotides in length. RNA transcription was generally terminated byheating the reaction to 65C for fifteen minutes. RNA transcriptionproducts were precipitated in ethanol, washed, air dried and resuspendedin RNAse free water to a concentration of about 1 microgram permicroliter. Most transcripts which took advantage of the opposing T7promoter strategy outlined above produced double stranded RNA in the invitro transcription reaction, however, a higher yield of double strandedRNA was obtained by heating the purified RNA to 65C and then slowlycooling to room temperature to ensure proper annealing of sense andantisense RNA segments. Double stranded RNA products were then incubatedwith DNAse I and RNAse at 37C for one hour to remove any DNA or singlestranded RNA present in the mixture. Double stranded RNA products werepurified over a column according to the manufacturers' instructions(AMBION MEGASCRIPT RNAi KIT) and resuspended in 10 mM Tris-HCl buffer(pH 7.5) or RNAse free water to a concentration of between 0.1 and 1.0microgram per microliter.

A sample of double stranded RNA was either added directly to each wellcontaining insect diet as indicated above, or was modified prior tobeing added to insect diet. Modification of double stranded RNA followedthe instructions for RNAse III (AMBION CORPORATION, Austin, Tex.) orDICER (STRATAGENE, La Jolla, Calif.) provided by the manufacturer. RNAseIII digestion of double stranded RNA produced twenty-one and twenty-twonucleotide duplexes containing 5′ phosphorylated ends and 3′ hydroxylends with 2-3 base overhangs, similar to the ˜21-26 base pair duplexedshort interfering RNA (siRNA) fragments produced by the dicer enzyme inthe eukaryotic pathway identified by Hamilton et al. (Science, 1999,286:950-952) and Elbashir et al (Genes & Development, 2001, 15:188-200).This collection of short interfering RNA duplexes was further purifiedand a sample characterized by polyacrylamide gel electrophoresis todetermine the integrity and efficiency of duplex formation. The purityand quantity of the sample was then determined by spectrophotometry at awavelength of 250 nanometers, and unused sample retained for further useby storage at −20C.

Samples of siRNA or full length double stranded RNA (dsRNA) weresubjected to bioassay with a selected number of target pests. Varyingdoes of dsRNA or siRNA were applied as an overlay to corn rootwormartificial diet according to the following procedure. Diabroticavirgifera virgifera (WCR) eggs were obtained from Crop Characteristics,Inc., Farmington, Minn. The non-diapausing WCR eggs were incubated insoil for about 13 days at 24C, 60% relative humidity, in completedarkness. On day 13 the soil containing WCR eggs was placed between #30and #60 mesh sieves and the eggs were washed out of the soil using ahigh pressure garden hose. The eggs were surface disinfested by soakingin LYSOL for three minutes, rinsed three times with sterile water,washed one time with a 10% formalin solution and then rinsed threeadditional times in sterile water. Eggs treated in this way weredispensed onto sterile coffee filters and hatched overnight at 27C, 60%relative humidity, in complete darkness.

Insect diet was prepared essentially according to Pleau et al.(Entomologia Experimentalis et Applicata, 2002, 105:1-11), with thefollowing modifications. 9.4 grams of SERVA agar was dispensed into 540milliliters of purified water and agitated until the agar was thoroughlydistributed. The water/agar mixture was heated to boiling to completelydissolve the agar, then poured into a WARING blender. The blender wasmaintained at low speed while 62.7 grams of BIO-SERV DIET mix (F9757),3.75 grams lyophilized corn root, 1.25 milliliters of green foodcoloring, and 0.6 milliliters of formalin was added to the hot agarmixture. The mixture was then adjusted to pH 9.0 with the addition of a10% potassium hydroxide stock solution. The approximately 600 millilitervolume of liquid diet was continually mixed at high speed and maintainedat from about 48C to about 60C using a sterilized NALGENE coatedmagnetic stir bar on a magnetic stirring hot plate while being dispensedin aliquots of 200 microliters into each well of FALCON 96-well roundbottom microtiter plates. The diet in the plates was allowed to solidifyand air dry in a sterile biohood for about ten minutes.

Thirty (30) microliter volumes of test samples containing either controlreagents or double stranded RNA in varying quantities was overlayed ontothe surface of the insect diet in each well using a micro-pipettorrepeater. Insect diet was allowed to stand in a sterile biohood for upto one half hour after application of test samples to allow the reagentsto diffuse into the diet and to allow the surface of the diet to dry.One WCR neonate larva was deposited to each well with a fine paintbrush.Plates were then sealed with MYLAR and ventilated using an insect pin.12-72 insect larvae were tested per dose depending on the design of theassay. The bioassay plates were incubated at 27C, 60% relative humidityin complete darkness for 12-14 days. The number of surviving larvae perdose was recorded at the 12-14 day time point. Larval mass wasdetermined using a suitable microbalance for each surviving larva. Datawas analyzed using JMP©4 statistical software (SAS Institute, 1995) anda full factorial ANOVA was conducted with a Dunnet's tet to look fortreatment effects compared to the untreated control (P<0.05). ATukey-Kramer post hoc test was performed to compare all pairs of thetreatments (P<0.05).

The following nucleotide sequences were derived first as cDNA sequencesidentified in a corn rootworm mid-gut cDNA library (Andersen et al.,ibid), and were adapted for use in constructing double stranded RNAmolecules for use in testing the efficacy of inhibiting a biologicalfunction in a pest by feeding double stranded RNA molecules in the dietof the pest.

A Chd3 Homologous Sequence

CHD genes have been identified in numerous eukaryotes, and thecorresponding proteins are proposed to function as chromatin-remodelingfactors. The term CHD is derived from the three domains of sequencehomology found in CHD proteins: a chromo (chromatin organizationmodifier) domain, a SNF2-related helicase/ATPase domain, and aDNA-binding domain, each of which is believed to confer a distinctchromatin-related activity. CHD proteins are separated into twocategories based on the presence or absence of another domain ofsequence homology, a PHD zinc finger domain, typically associated withchromatin related activity. CHD3 related proteins possess a PHD zincfinger domain, but CHD1 related proteins do not. Experimentalobservations have suggested a role for CHD3 proteins in repression oftranscription, and in some species have been shown to be a component ofa complex that contains histone deacetylase as a subunit. Deacetylationof histones is correlated with transcriptional inactivation, and so CHD3proteins have been implicated to function as repressors of transcriptionby virtue of being a component of a histone deacetylase complex (Ogas etal., 1999, PNAS 96:13839-13844). Thus, suppression of CHD3 proteinsynthesis may be a useful target for double stranded RNA mediatedinhibition of invertebrate pests.

SEQ ID NO:15 corresponds to a CRW midgut cDNA nucleotide sequence, theamino acid sequence translation of which was annotated to be homologousto a Drosophila melanogaster CHD3 amino acid sequence (GenBank accessionNo. AF007780). SEQ ID NO:16 and SEQ ID NO:17 correspond respectively toforward and reverse genome amplification primers (i.e., a primer pair)for use in producing an amplicon from CRW genomic DNA, from CRW mRNApools, or from a cDNA produced from such pools. The sequence of such anamplicon corresponds to a part of a CRW gene encoding a homolog of a D.melanogaster CHD3 amino acid sequence. SEQ ID NO:16 contains a T7polymerase promoter sequence at its 5′ end (nucleotides 1-23) linked toa CRW genome primer sequence (arbitrarily assigned as the forward primersequence) depicted as set forth at SEQ ID NO:16 from nucleotide position24-45, which corresponds to nucleotide position 31 through nucleotideposition 52 as set forth in SEQ ID NO:15. SEQ ID NO:17 contains a T7polymerase promoter sequence at its 5′end as set forth from nucleotideposition 1-23. The T7 promoter sequence is linked at its 3′ end to anarbitrarily assigned reverse genome primer sequence corresponding tonucleotide position 24-44 as set forth in SEQ ID NO:17, the reversecomplement of the sequence as set forth in SEQ ID NO:15 from nucleotideposition 298-319. Using the primer pair consisting of SEQ ID NO:16 andSEQ ID NO:17 in an amplification reaction with CRW genomic DNA as atemplate, a 335 base pair amplicon comprising the nucleotide sequence asset forth in SEQ ID NO:18 is produced, corresponding to a part of theCRW genome that encodes a protein exhibiting about 66% identity to aDrosophila melanogaster CHD3 amino acid sequence. Nucleotides atposition 1-23 and the reverse complement of nucleotides at position314-335 as set forth in SEQ ID NO:8 correspond to the T7 promotersequences at either end of the amplicon. The amplified genomicnucleotide sequence as set forth in SEQ ID NO:18 from nucleotide 24through nucleotide 313 corresponds substantially to the reported cDNAnucleotide sequence as set forth at SEQ ID NO:15 from nucleotide 31through nucleotide 319, except that nucleotides at positions 63, 87,117, 177, 198, 213, 219-220, 246, 249, and 261 as set forth in SEQ IDNO:15 were reported to be T, T, G, G, G, T, T, T, C, C, and Arespectively while the corresponding positions in alignment with SEQ IDNO:18 contained C, C, A, A, A, C, A, C, G A, and G at nucleotidepositions 56, 80, 110, 170, 191, 206, 212-213, 239, 242, and 254. Thisdifference corresponds to about a 4% difference in the nucleotidesequence composition between the previously reported cDNA sequence andthe sequence of the amplicon produced from genome DNA template,consistent with the earlier report that the cDNA sequence was likelyless than 99% accurate (Andersen et al., ibid.).

An amplicon exhibiting the sequence corresponding to SEQ ID NO:18 wascloned into a plasmid vector capable of replication in E. coli andsufficient amounts of plasmid DNA was recovered to allow for in vitro T7RNA polymerase transcription from the embedded convergent T7 promotersat either end of the cloned fragment. Double stranded RNA was producedand subjected to bioassay; one RNA segment consisting of the sequence asset forth in SEQ ID NO:18 from about nucleotide position 24 at leastthrough about nucleotide position 313 except that a uridine residue ispresent at each position in which a thymidine residue is shown in SEQ IDNO:18, the other RNA segment being substantially the reverse complementof the nucleotide sequence as set forth in SEQ ID NO:18 from aboutnucleotide position 313 at least through about nucleotide position 24,uridines appropriately positioned in place of thymidines. A sample ofdouble stranded RNA (dsRNA) was treated with DICER or with RNAse III toproduce sufficient quantities of small interfering RNA's (siRNA).Samples containing 0.15 parts per million siRNA or dsRNA were overlayedonto CRW diet bioassay as described above and larvae were allowed tofeed for 13 days. CRW larvae feeding on diet containing dsRNAcorresponding to all or a part of the sequence as set forth at SEQ IDNO:15 exhibited significant growth inhibition and mortality compared tocontrols.

Other nucleotide sequences derived from CRW were also tested in bioassayin parallel with the CHD3 sequences including nucleotide sequencesannotated to likely encode CRW equivalents of proteins such asbeta-tubulin protein, 40 kDa V-ATPase subunit protein, elongation factorproteins EF1α and EF1α 48D, 26S proteosome subunit p28 protein, juvenilehormone epoxide hydrolase protein, swelling dependent chloride channelprotein, glucose-6-phosphate 1-dehydrogenase protein, actin 42A protein,ADP-ribosylation factor 1 protein, transcription factor IIB, chitinaseproteins, and a ubiquitin conjugating enzyme.

A Beta-Tubulin Homologous Sequence

Tubulin proteins are important structural components of many cellularstructures in all eukaryote cells and principally in the formation ofmicrotubules. Inhibition of microtubule formation in cells results incatastrophic effects including interference with the formation ofmitotic spindles, blockage of cell division, and the like. Therefore,suppression of tubulin protein formation may be a useful target fordouble stranded RNA mediated inhibition.

A beta-tubulin related sequence derived from CRW was identified for usein the present invention. SEQ ID NO:29 corresponds to a CRW midgut cDNAnucleotide sequence, the amino acid sequence translation of which wasannotated to be homologous in part to a Manduca sexta beta-1-tubulinamino acid sequence and in part to a Drosophila melanogasterbeta-1-tubulin amino acid sequence (GenBank accession No.'s AF030547 andM20419 respectively). SEQ ID NO:30 and SEQ ID NO:31 correspondrespectively to forward and reverse genome amplification primers (i.e.,a primer pair) for use in producing an amplicon from CRW genomic DNA,from CRW mRNA pools, or from a cDNA produced from such pools. Thesequence of such an amplicon corresponds to all or a part of a CRW geneencoding a beta-tubulin protein. SEQ ID NO:30 and SEQ ID NO:31 eachcontain a 23 nucleotide T7 promoter sequence from nucleotide positions1-23 respectively. Nucleotides 24-44 as set forth in SEQ ID NO:30correspond to nucleotides 96-116 as set forth in SEQ ID NO:29.Nucleotides 24-44 as set forth in SEQ ID NO:31 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:29 from nucleotides428-448. Using the primer pair consisting of SEQ ID NO:30 and SEQ IDNO:31 in an amplification reaction with CRW genomic DNA as a template, a399 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:32 is produced, corresponding substantially to a part ofthe CRW genome encoding a protein exhibiting substantial identity to abeta-tubulin protein homolog present in Drosophila melanogaster andManduca sexta. The nucleotide sequence as set forth in SEQ ID NO:32corresponds substantially to the nucleotide sequence as set forth at SEQID NO:29 from nucleotides 96-448. No sequence differences were observedbetween the genome amplicon sequence and the corresponding sequencewithin the cDNA sequence.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:32 wascloned into a plasmid vector, and sufficient amounts of plasmid DNA wasrecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA was produced and a sample was subjected to bioassay;one RNA segment, the sense strand, consisting of the sequence as setforth in SEQ ID NO:32 from about nucleotide position 24 at least throughabout nucleotide position 376 except that a uridine residue is presentat each position in which a thymidine residue is shown in SEQ ID NO:32,the reverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:32 from about nucleotide position 376 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) wastreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA were overlayed onto CRW diet bioassay asdescribed above and larvae were allowed to feed for 13 days. CRW larvaefeeding on diet containing dsRNA corresponding to all or a part of thesequence as set forth at SEQ ID NO:29 exhibited significant growthinhibition and mortality compared to controls.

A 40 kDa V-ATPase homologous Sequence

Energy metabolism within subcellular organelles in eukaryotic systems isan essential function. Vacuolar ATP synthases are involved inmaintaining sufficient levels of ATP within vacuoles. Therefore,vacuolar ATP synthases may be a useful target for double stranded RNAmediated inhibition.

A nucleotide sequence encoding a protein that displayed similarity to a40 kDa V-ATPase was derived from CRW. An amino acid sequence translationof SEQ ID NO:43 exhibited homology to a Manduca sexta 40-kDa V-ATPasesubunit amino acid sequence (GenBank accession No. X98825). SEQ ID NO:44and SEQ ID NO:45 correspond respectively to forward and reverse genomeamplification primers (i.e., a primer pair) for use in producing anamplicon from CRW genomic DNA, CRW mRNA pools, or a CRW cDNA derivedfrom such pools. The sequence of such an amplicon should correspond toall or a part of a CRW gene encoding a 40 kDa V-ATPase homologousprotein. However, the nucleotide sequence of an amplicon derived usingCRW genomic DNA as template was inconsistent with the reported cDNAsequence as set forth in SEQ ID NO:43.

SEQ ID NO:44 and SEQ ID NO:45 represent thermal amplification primers.Each primer contains a 23 nucleotide T7 promoter sequence fromnucleotide positions 1-23 respectively. Nucleotides 24-40 as set forthin SEQ ID NO:44 correspond to nucleotides 95-111 as set forth in SEQ IDNO:43. Nucleotides 24-43 as set forth in SEQ ID NO:45 correspond to thereverse complement of the sequence as set forth in SEQ ID NO:43 fromnucleotides 362-381. Using the primer pair consisting of SEQ ID NO:44and SEQ ID NO:45 in an amplification reaction with CRW genomic DNAtemplate, a 291 base pair amplicon comprising the nucleotide sequence asset forth in SEQ ID NO:46 is produced. SEQ ID NO:46 from nucleotide 24through nucleotide 268 exhibited only about 50% homology to thenucleotide sequence as set forth in SEQ ID NO:43 based on aMartinez/Needleman-Wunsch DNA alignment. The amplicon sequence derivedusing the selected thermal amplification primer pair was inconsistentwith the reported sequence as set forth in SEQ ID NO:43. Preferably, anamplicon is produced using a CRW mRNA pool or a cDNA derived from suchpool.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:43 fromabout nucleotide position 95 through about nucleotide position 381 wasproduced and cloned into a plasmid vector, and sufficient amounts ofplasmid DNA were recovered to allow for in vitro T7 RNA polymerasetranscription from the embedded convergent T7 promoters at either end ofthe cloned amplicon. Double stranded RNA was produced and a samplesubjected to bioassay; one RNA segment, the sense strand, consisting ofthe sequence as set forth in SEQ ID NO:43 from about nucleotide position95 at least through about nucleotide position 381 except that a uridineresidue is present at each position in which a thymidine residue isshown in SEQ ID NO:43, and the reverse complement RNA segment, or theanti-sense strand, being substantially the reverse complement of thenucleotide sequence as set forth in SEQ ID NO:43 from about nucleotideposition 381 at least through about nucleotide position 95, uridinesappropriately positioned in place of thymidines. A sample of doublestranded RNA (dsRNA) was treated with DICER or with RNAse III to producesufficient quantities of small interfering RNA's (siRNA). Samplescontaining 0.15 parts per million siRNA or dsRNA were overlayed onto CRWdiet bioassay as described above and larvae were allowed to feed for 13days. CRW larvae feeding on diet containing dsRNA corresponding to allor a part of the sequence as set forth at SEQ ID NO:43 exhibitedsignificant growth inhibition and mortality compared to controls.

A EF1α Homologous Sequence

Transcription elongation and transcription termination factors areessential to metabolism and may be advantageous targets for doublestranded RNA mediated inhibition.

At least two CRW cDNA sequences were identified for use in the presentinvention that were predicted to encode elongation factor 1 alpha (EF1α)homologs.

The amino acid sequence translation of a singleton CRW cDNA sequence asset forth in SEQ ID NO:47 exhibited homology to a Drosophilamelanogaster EF-1-alpha amino acid sequence (GenBank Accession No.X06870). Other sequences predicted to encode EF1α homologous proteinswere also identified from within the CRW cDNA midgut library. Thesesequences were aligned to produce a UNIGENE sequence as set forth in SEQID NO:51 which was predicted to encode an EF1α protein homolog referredto herein as 48D. Several of the sequences comprised within thissingleton were predicted to encode amino acid sequences exhibitinghomology to various EF1α homologous protein sequences including but notlimited to a Bombyx mori EF1α (GenBank Accession No. D13338), a Alterniaspecies EF1α (GenBank Accession No. X03704), a Spragueia leo EF1α(GenBank Accession No. U85680), a Apis mellifera EF1α (GenBank AccessionNo. AF015267), a Anisakis simplex EF1α (GenBank Accession No. AJ250539),a Papaipema species EF1α (GenBank Accession No. AF151628), a Ephedruspersicae EF1α (GenBank Accession No. Z83663), a Papilio garamas EF1α(GenBank Accession No. AF044833), a Alysia lucicola EF1α (GenBankAccession No. Z83667), a Bracon species EF1α (GenBank Accession No.Z83669), a Histeromerus mystacinus EF1α (GenBank Accession No. Z83666),and a Caenorhabditis elegans EF1α (GenBank Accession No. U41534).

One CRW cDNA sequence predicted to encode a part of an EF1α homolog isreferred to herein as the B2 sequence and is set forth at SEQ ID NO:47.SEQ ID NO:48 and SEQ ID NO:49 correspond respectively to forward andreverse genome amplification primers (i.e., a primer pair, withreference to corresponding or reverse complement sequences as set forthin SEQ ID NO:47) for use in producing an amplicon from CRW genomic DNA,CRW mRNA pools, or from a cDNA derived from such mRNA pools. Thesequence of such an amplicon should correspond to all or a part of a CRWgene encoding an EF1α homologous protein. However, the nucleotidesequence of an amplicon derived when CRW genomic DNA was used astemplate was inconsistent with the reported cDNA sequence as set forthin SEQ ID NO:47.

SEQ ID NO:48 and SEQ ID NO:49 represent sequences for thermalamplification primers. Each primer contains a 23 nucleotide T7 promotersequence from nucleotide positions 1-23 respectively. Nucleotides 24-44as set forth in SEQ ID NO:48 correspond to nucleotides 8-29 as set forthin SEQ ID NO:47. Nucleotides 24-42 as set forth in SEQ ID NO:49correspond to the reverse complement of the sequence as set forth in SEQID NO:47 from nucleotides 310-328. Using the primer pair consisting ofSEQ ID NO:48 and SEQ ID NO:49 in an amplification reaction with CRWgenomic DNA as a template, a 933 base pair amplicon comprising thenucleotide sequence as set forth in SEQ ID NO:50 was produced. Thenucleotide sequence as set forth in SEQ ID NO:50 was inconsistent withthe nucleotide sequence from nucleotide position 8 through nucleotideposition 328 as set forth in SEQ ID NO:47. Preferably an amplicon isproduced using a CRW mRNA pool or a cDNA derived from such pool, such asfor example, SEQ ID NO:47.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:47 fromabout nucleotide position 8 through about nucleotide position 328 wasproduced using CRW mRNA pools or cDNA prepared from such pools, andcloned into a plasmid vector. Sufficient amounts of plasmid DNA wererecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA was produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:47 from about nucleotide position 8 at least through aboutnucleotide position 328 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:47, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:47 from about nucleotide position 328 at leastthrough about nucleotide position 8, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) wastreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA were overlayed onto CRW diet bioassay asdescribed above and larvae were allowed to feed for 13 days. CRW larvaefeeding on diet containing dsRNA corresponding to all or a part of thesequence as set forth at SEQ ID NO:47 exhibited significant growthinhibition and mortality compared to controls.

The sequence as set forth in SEQ ID NO:51 was used to design a primerpair for use in amplifying a CRW genomic DNA sequence encoding a EF1α48D homologous protein sequence. SEQ ID NO:52 and SEQ ID NO:53correspond respectively to forward and reverse genome amplificationprimers (i.e., a primer pair). SEQ ID NO:52 and SEQ ID NO:53 eachcontain a 23 nucleotide T7 promoter sequence from nucleotide positions1-23 respectively. Nucleotides 24-41 as set forth in SEQ ID NO:52correspond to nucleotides 61-79 as set forth in SEQ ID NO:51.Nucleotides 24-45 as set forth in SEQ ID NO:53 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:51 from nucleotides562-583. Using the primer pair consisting of SEQ ID NO:52 and SEQ IDNO:53 in an amplification reaction with CRW genomic DNA as a template, a569 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:54 is produced, corresponding substantially to a part ofthe CRW genome encoding a protein exhibiting substantial identity to aEF1α protein also present in Drosophila melanogaster. The nucleotidesequence as set forth in SEQ ID NO:54 from about nucleotide 24 throughabout nucleotide 546 corresponds substantially to the nucleotidesequence as set forth at SEQ ID NO:51 from about nucleotides 61-583. Nosequence differences were observed between the genome amplicon sequenceand the corresponding sequence within the cDNA sequence.

The amplicon exhibiting the sequence corresponding to SEQ ID NO:54 wascloned into a plasmid vector, and sufficient amounts of plasmid DNA wasrecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA was produced and a sample was subjected to bioassay;one RNA segment, the sense strand, consisting of the sequence as setforth in SEQ ID NO:54 from about nucleotide position 24 at least throughabout nucleotide position 546 except that a uridine residue is presentat each position in which a thymidine residue is shown in SEQ ID NO:54,and the reverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:54 from about nucleotide position 546 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) wastreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA were overlayed onto CRW diet bioassay asdescribed above and larvae were allowed to feed for 13 days. CRW larvaefeeding on diet containing dsRNA corresponding to all or a part of thesequence as set forth at SEQ ID NO:54 exhibited significant growthinhibition and mortality compared to controls.

A 26S Proteosome Subunit p28 Homologous Sequence

The 26S proteasome is a large, ATP-dependent, multi-subunit proteasethat is highly conserved in all eukaryotes. It has a general function inthe selective removal of various short-lived proteins that are firstcovalently linked to ubiquitin and then subsequently degraded by the 26Sproteasome complex. The ubiquitin pathway plays an important role in thecontrol of the cell cycle by the specific degradation of a number ofregulatory proteins including mitotic cyclins and inhibitors ofcyclin-dependent kinases such as p27 of mammalian cells. Thus, thesuppression of 26S proteasome synthesis and suppression of synthesis ofits component subunits may be preferred targets for double stranded RNAmediated inhibition. (Smith et al., Plant Phys. 1997, 113:281-291).

A cDNA sequence derived from a CRW mid-gut library was identified asbeing partially homologous to a 26S proteosome subunit amino acidsequence and was used in the present invention. SEQ ID NO:55 correspondssubstantially to a CRW midgut cDNA nucleotide sequence. An amino acidsequence translation of SEQ ID NO:55 exhibited homology to a 26Sproteasome subunit p28 protein (GenBank Accession No. AB009619). SEQ IDNO:56 and SEQ ID NO:57 correspond respectively to forward and reversegenome amplification primers (i.e., a primer pair) for use in producingan amplicon from CRW genomic DNA, from CRW mRNA pools, and from cDNAproduced from such pools. An amplicon produced in this way shouldexhibit a sequence that encodes all or a part of a CRW gene encoding ahomolog of a 26S proteosome subunit protein. SEQ ID NO:56 and SEQ IDNO:57 each contain a 23 nucleotide T7 promoter sequence from nucleotidepositions 1-23 respectively. Nucleotides 24-46 as set forth in SEQ IDNO:56 correspond to nucleotides 130-152 as set forth in SEQ ID NO:45.Nucleotides 24-41 as set forth in SEQ ID NO:57 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:55 from nucleotides423-440. Using the primer pair consisting of SEQ ID NO:55 and SEQ IDNO:57 in an amplification reaction with CRW genomic DNA as a template, a1113 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:58 was produced. The sequence as set forth in SEQ ID NO:58did not correspond to the sequence as set forth in SEQ ID NO:55, andtherefore was inconsistent with the reported cDNA sequence as set forthin SEQ ID NO:55. It is preferred that an amplicon is produced using aCRW mRNA pool or a cDNA derived from such pool.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:55 fromabout nucleotide 130 through about nucleotide 440 was produced andcloned into a plasmid vector, and sufficient amounts of plasmid DNA wererecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA was produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:55 from about nucleotide position 130 at least throughabout nucleotide position 440 except that a uridine residue is presentat each position in which a thymidine residue is shown in SEQ ID NO:55,and the reverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:55 from about nucleotide position 440 at leastthrough about nucleotide position 110, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) wastreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA were overlayed onto CRW diet bioassay asdescribed above and larvae were allowed to feed for 13 days. CRW larvaefeeding on diet containing dsRNA corresponding to all or a part of thesequence as set forth at SEQ ID NO:55 exhibited significant growthinhibition and mortality compared to controls.

A Juvenile Hormone Epoxide Hydrolase Homologous Sequence

Insect juvenile hormone controls and regulates a variety of necessarybiological processes within the insect life cycle including but notnecessarily limited to metamorphosis, reproduction, and diapause.Juvenile hormone (JH) concentrations are required to peak at appropriatetimes within the haemolymph of the larval form of an insect pest, inparticular lepidopteran and coleopteran larvae, and then must bedegraded in order to terminate the effects of the hormone response.Enzymes involved in decreasing the concentration of juvenile hormone areeffective through two primary pathways of metabolic degradation. Onepathway involves juvenile hormone esterse (JHE), which hydrolyzes themethyl ester providing the corresponding acid. The second pathwayutilizes juvenile hormone epoxide hydrolase (JHEH) to achieve hydrolysisof the epoxide, resulting in formation of the diol. The contribution ofJHE in the degradation of JH is well understood and has been found to beinvariate between the lepidoptera and coleoptera species. Inhibition ofJH esterase has been associated with severe morphological changesincluding but not limited to larval wandering, deferred pupation, anddevelopment of malformed intermediates. In contrast, the contribution ofJHEH in JH metabolism is less well understood and had been shown to varybetween the species, but recent studies point to evidence that suggeststhat JHEH may be the primary route of metabolism of JH (Brandon J.Fetterolf, Doctoral Dissertation, N.C. State University (Feb. 10, 2002)Synthesis and Analysis of Mechanism Based Inhibitors of Juvenile HormoneEpoxide Hydrolase from Insect Trichoplusia ni). In any event, disruptionof either JH degradation pathway using gene suppression technology couldbe an effective target for double stranded RNA mediated pest inhibition.

An insect juvenile hormone epoxide hydrolase homologous sequence derivedfrom CRW was identified for use in the present invention. SEQ ID NO:59corresponds substantially to a CRW midgut cDNA nucleotide sequence. Anamino acid sequence translation of SEQ ID NO:59 predicted homology to ajuvenile hormone epoxide hydrolase (JHEH) in Manduca Sexta (GenBankAccession No. U46682). SEQ ID NO:60 and SEQ ID NO:61 correspondrespectively to forward and reverse amplification primers (i.e., aprimer pair) for use in producing an amplicon from CRW genomic DNA, CRWmRNA pools, or a CRW cDNA derived from such pools. The sequence of suchan amplicon should correspond to all or a part of a CRW gene encoding aJHEH homologous protein. SEQ ID NO:60 and SEQ ID NO:61 each contain a 23nucleotide T7 promoter sequence from nucleotide positions 1-23respectively. Nucleotides 24-42 as set forth in SEQ ID NO:60 correspondto nucleotides 7-26 as set forth in SEQ ID NO:59. Nucleotides 24-44 asset forth in SEQ ID NO:61 correspond to the reverse complement of thesequence as set forth in SEQ ID NO:59 from nucleotides 360-380. Usingthe primer pair consisting of SEQ ID NO:60 and SEQ ID NO:61 in anamplification reaction with CRW genomic DNA as a template, a 95 basepair amplicon comprising the nucleotide sequence as set forth in SEQ IDNO:63 was produced. The amplicon sequence did not correspond to the cDNAsequence as set forth in SEQ ID NO:59. Preferably, an amplicon isproduced using a CRW mRNA pool or a cDNA derived from such pool as thetemplate nucleotide sequence in the amplification reaction.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:59 iscloned into a plasmid vector, and sufficient amounts of plasmid DNA arerecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample is subjected to bioassay;one RNA segment, the sense strand, consisting of the sequence as setforth in SEQ ID NO:59 from about nucleotide position 7 at least throughabout nucleotide position 380 except that a uridine residue is presentat each position in which a thymidine residue is shown in SEQ ID NO:59,and the reverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:59 from about nucleotide position 380 at leastthrough about nucleotide position 7, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae are allowed to feed for 13 days. CRW larvae feeding ondiet containing dsRNA corresponding to all or a part of the sequence asset forth at SEQ ID NO:59 exhibit significant growth inhibition andmortality compared to controls.

A Swelling Dependent Chloride Channel Protein Homologous Sequence

Swelling dependent chloride channel proteins have been postulated toplay a critical role in osmoregulation in eukaryotic animal cellsystems. Therefore, a nucleotide sequence exhibiting the ability toexpress an amino acid sequence that exhibits homology to previouslyidentified swelling dependent chloride channel proteins may be a usefultarget for RNA inhibition in a pest.

A swelling dependent chloride channel (SDCC) amino acid sequence homologwas deduced from a CRW cDNA library and used in the present invention.SEQ ID NO:64 corresponds substantially to a CRW midgut cDNA nucleotidesequence. The amino acid sequence translation of SEQ ID NO:64 wasdetermined to be homologous to a SDCC protein in the zebra fish Daniorerio (GenBank Accession No. Y08484). SEQ ID NO:65 and SEQ ID NO:66correspond respectively to forward and reverse thermal amplificationprimers (i.e., a primer pair) for use in producing an amplicon from CRWgenomic DNA, from CRW mRNA pools, or from cDNA derived from such pools.The sequence of such an amplicon should correspond to all or a part of aCRW gene encoding a SDCC homologous protein. SEQ ID NO:65 and SEQ IDNO:66 each contain a 23 nucleotide T7 promoter sequence from nucleotidepositions 1-23 respectively. Nucleotides 24-43 as set forth in SEQ IDNO:65 correspond to nucleotides 78-97 as set forth in SEQ ID NO:64.Nucleotides 24-41 as set forth in SEQ ID NO:66 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:64 from nucleotides332-349. Using the primer pair consisting of SEQ ID NO:65 and SEQ IDNO:66 in an amplification reaction with CRW genomic DNA as a template, a318 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:67 is produced, corresponding substantially to a part ofthe CRW genome encoding a protein exhibiting substantial identity to aSDCC protein. The nucleotide sequence as set forth in SEQ ID NO:67 fromabout nucleotide 24 through about nucleotide 295 correspondssubstantially to the nucleotide sequence as set forth at SEQ ID NO:64from nucleotides 78-349.

The amplicon exhibiting the sequence corresponding to SEQ ID NO:67 iscloned into a plasmid vector, and sufficient amounts of plasmid DNA arerecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:67 from about nucleotide position 24 at least through aboutnucleotide position 295 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:67, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:67 from about nucleotide position 295 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:67 exhibit significant growth inhibition andmortality compared to controls.

A Glucose-6-Phosphate 1-Dehydrogenase Protein Homologous Sequence

Glucose-6-phosphate 1-dehydrogenase protein (G6PD) catalyzes theoxidation of glucose-6-phosphate to 6-phosphogluconate whileconcomitantly reducing the oxidized form of nicotinamide adeninedinucleotide phosphate (NADP+) to NADPH. NADPH is known in the art as arequired cofactor in many eukaryotic biosynthetic reactions, and isknown to maintain glutathione in its reduced form. Reduced glutathioneacts as a scavenger for dangerous oxidative metabolites in eukaryoticcells, and with the assistance of the enzyme glutathione peroxidase,convert harmful hydrogen peroxide to water (Beutler et al., 1991, N.Engl. J. Med. 324:169-174). Therefore, G6PD may be a preferable targetfor double stranded RNA mediated inhibition in an invertebrate pest.

A glucose-6-phosphate 1-dehydrogenase protein (G6PD) homologous aminoacid sequence was deduced from a CRW cDNA library and used in thepresent invention. SEQ ID NO:68 corresponds substantially to a CRWmidgut cDNA nucleotide sequence. The amino acid sequence translation ofSEQ ID NO:68 was determined to exhibit homology to a G6PD protein in aray-finned fish species (GenBank Accession No. U72484). SEQ ID NO:69 andSEQ ID NO:70 correspond respectively to forward and reverse genomeamplification primers (i.e., a primer pair) for use in producing anamplicon from CRW genomic DNA, from CRW mRNA pools, or from cDNA derivedfrom such pools. The sequence of such an amplicon should correspond toall or a part of a CRW gene encoding a G6PD homologous protein. SEQ IDNO:69 and SEQ ID NO:70 each contain a 23 nucleotide T7 promoter sequencefrom nucleotide positions 1-23 respectively. Nucleotides 24-46 as setforth in SEQ ID NO:69 correspond to nucleotides 113-136 as set forth inSEQ ID NO:68. Nucleotides 24-45 as set forth in SEQ ID NO:70 correspondto the reverse complement of the sequence as set forth in SEQ ID NO:68from nucleotides 373-394. Using the primer pair consisting of SEQ IDNO:69 and SEQ ID NO:70 in an amplification reaction with CRW genomic DNAas a template, a 328 base pair amplicon comprising the nucleotidesequence as set forth in SEQ ID NO:71 is produced, correspondingsubstantially to a part of the CRW genome encoding a protein exhibitinghomology to a G6PD protein. The nucleotide sequence as set forth in SEQID NO:71 from about nucleotide 24 through about nucleotide 305corresponds substantially to the nucleotide sequence as set forth at SEQID NO:68 from nucleotides 113-394.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:71 iscloned into a plasmid vector, and sufficient amounts of plasmid DNA arerecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:71 from about nucleotide position 24 at least through aboutnucleotide position 305 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:71, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:71 from about nucleotide position 305 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:71 exhibit significant growth inhibition andmortality compared to controls.

A Act42A Protein Homologous Sequence

Actin is a ubiquitous and highly conserved eukaryotic protein requiredfor cell motility and locomotion (Lovato et al., 2001, Insect Mol. Biol.20:333-340). A number of CRW cDNA sequences were identified that werepredicted to likely encode actin or proteins exhibiting amino acidsequence structure related to actin proteins. Therefore, genes encodingactin homologues in a pest cell may be useful targets for doublestranded RNA mediated inhibition.

One UNIGENE cluster identified within a corn rootworm midgut cDNAlibrary (Cluster 156_(—)1) consisted of several singleton EST sequencesthat were each predicted to encode all or part of actin homologousproteins. Upon alignment of these singletons into the cluster, aconsensus sequence was derived as set forth in SEQ ID NO:72 that waspredicted to encode an actin protein homolog. Homologous actin proteinsequences within the annotation group included but were not limited toDrosophila melanogaster actin 3 fragments, a Helicoverpa armigeracytoplasmin actin A3a (GenBank Accession No. X97614), a Drosophilamelanogaster actin (GenBank Accession No. X06383), a hemichordateSaccoglossus kowalevskii actin messenger RNA sequence, and aStrongylocentrotus purpuratus actin (GenBank Accession No. X05739).

SEQ ID NO:73 and SEQ ID NO:74 correspond respectively to forward andreverse genome amplification primers (i.e., a primer pair) for use inproducing an amplicon from CRW genomic DNA, CRW mRNA pools, or from acDNA derived from such pools. The sequence of such an amplicon shouldcorrespond to all or a part of a CRW gene encoding an actin homologousprotein. SEQ ID NO:73 and SEQ ID NO:74 each contain a 23 nucleotide T7promoter sequence from nucleotide positions 1-23 respectively.Nucleotides 24-45 as set forth in SEQ ID NO:73 correspond to nucleotides14-35 as set forth in SEQ ID NO:72. Nucleotides 24-45 as set forth inSEQ ID NO:74 correspond to the reverse complement of the sequence as setforth in SEQ ID NO:72 from nucleotides 449-470. Using the primer pairconsisting of SEQ ID NO:73 and SEQ ID NO:74 in an amplification reactionwith CRW genomic DNA as a template, a 503 base pair amplicon comprisingthe nucleotide sequence as set forth in SEQ ID NO:75 is produced,corresponding substantially to a part of the CRW genome encoding aprotein exhibiting homology to an actin protein. The nucleotide sequenceas set forth in SEQ ID NO:75 from about nucleotide 24 through aboutnucleotide 480 corresponds substantially to the nucleotide sequence asset forth at SEQ ID NO:72 from nucleotides 14-470.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:75 iscloned into a plasmid vector, and sufficient amounts of plasmid DNArecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:75 from about nucleotide position 24 at least through aboutnucleotide position 480 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:75, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:75 from about nucleotide position 480 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:75 exhibit significant growth inhibition andmortality compared to controls.

A ADP-Ribosylation Factor 1 Homologous Sequence

ADP ribosylation factors have been demonstrated to be essential in cellfunction in that they play integral roles in the processes of DNA damagerepair, carcinogenesis, cell death, and genomic stability. Thus, itwould be useful to be able to selectively disrupt transcription ofADP-ribosylation factors in invertebrate pest species using doublestranded RNA mediated inhibition.

A number of CRW cDNA sequences were identified that were predicted toencode amino acid sequences exhibiting homology to ADP-ribosylationfactor proteins. One UNIGENE cluster in particular (Cluster 88_(—)1) wascomposed of about thirty (30) EST singletons that were each predicted toencode all or part of actin homologous proteins. Upon alignment of thesesingletons into the cluster, a consensus sequence was derived as setforth in SEQ ID NO:76. An amino acid sequence translation of thesingleton CRW cDNA sequence comprising this cluster predicted an aminoacid sequence exhibiting homology to ADP-ribosylation factor homologs.ADP-ribosylation factor protein sequences exhibiting significanthomology to the deduced amino acid sequence from the ORF within SEQ IDNO:76 included but were not limited to a Drosophila melanogasterADP-ribosylation factor (GenBank Accession No. Y10618), a Drosophilaobscura ADP-ribosylation factor (GenBank Accession No. AF025798), aAnopheles gambiae ADP-ribosylation factor (GenBank Accession No.L11617), and a Australian sheep blowfly (Lucilia cuprina)ADP-ribosylation factor (GenBank Accession No. AF218587).

SEQ ID NO:77 and SEQ ID NO:78 correspond respectively to forward andreverse amplification primers (i.e., a primer pair) for use in producingan amplicon from CRW genomic DNA, CRW mRNA pools, or from cDNA sequencesderived from such pools. The sequence of such an amplicon shouldcorrespond to all or a part of a CRW gene encoding an ADP-ribosylationfactor homologous protein. SEQ ID NO:77 and SEQ ID NO:78 each contain a23 nucleotide T7 promoter sequence from nucleotide positions 1-23respectively. Nucleotides 24-42 as set forth in SEQ ID NO:77 correspondto nucleotides 70-88 as set forth in SEQ ID NO:76. Nucleotides 24-40 asset forth in SEQ ID NO:78 correspond to the reverse complement of thesequence as set forth in SEQ ID NO:76 from nucleotides 352-368. Usingthe primer pair consisting of SEQ ID NO:77 and SEQ ID NO:78 in anamplification reaction with CRW genomic DNA as a template, a 345 basepair amplicon comprising the nucleotide sequence as set forth in SEQ IDNO:79 is produced, corresponding substantially to a part of the CRWgenome encoding a protein exhibiting homology to an ADP-ribosylationfactor protein. The nucleotide sequence as set forth in SEQ ID NO:79from about nucleotide 24 through about nucleotide 322 correspondssubstantially to the nucleotide sequence as set forth at SEQ ID NO:76from nucleotides 70-368.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:79 iscloned into a plasmid vector, and sufficient amounts of plasmid DNArecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:79 from about nucleotide position 24 at least through aboutnucleotide position 322 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:79, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:79, from about nucleotide position 322 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:79 exhibit significant growth inhibition andmortality compared to controls.

A Transcription Factor IIB Protein Homologous Sequence

Transcription elongation and transcription termination factors, asindicated above, are essential to metabolism and may be advantageoustargets for double stranded RNA mediated inhibition to control oreliminate invertebrate pest infestation.

A CRW cDNA sequence was identified that was predicted to encode an aminoacid sequence exhibiting homology to a transcription factor IIB protein.SEQ ID NO:80 served as the basis for constructing a primer pair for usein amplifying a sequence from within the CRW genome encoding the mRNAthat formed the basis for this cDNA sequence.

SEQ ID NO:81 and SEQ ID NO:82 correspond respectively to forward andreverse thermal amplification primers (i.e., a primer pair) for use inproducing an amplicon from CRW genomic DNA, from CRW mRNA pools, or fromcDNA derived from such pools. The sequence of such an amplicon shouldcorrespond to all or a part of a CRW gene encoding a transcriptionfactor IIB homologous protein. SEQ ID NO:81 and SEQ ID NO:82 eachcontain a 23 nucleotide T7 promoter sequence from nucleotide positions1-23 respectively. Nucleotides 24-44 as set forth in SEQ ID NO:81correspond to nucleotides 4-24 as set forth in SEQ ID NO:80. Nucleotides24-44 as set forth in SEQ ID NO:82 correspond to the reverse complementof the sequence as set forth in SEQ ID NO:80 from nucleotides 409-429.Using the primer pair consisting of SEQ ID NO:81 and SEQ ID NO:82 in anamplification reaction with CRW genomic DNA as a template, a 472 basepair amplicon comprising the nucleotide sequence as set forth in SEQ IDNO:83 is produced, corresponding substantially to a part of the CRWgenome encoding a protein exhibiting homology to a transcription factorIIB protein. The nucleotide sequence as set forth in SEQ ID NO:83 fromabout nucleotide 24 through about nucleotide 449 correspondssubstantially to the nucleotide sequence as set forth at SEQ ID NO:80from nucleotides 4-429.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:83 iscloned into a plasmid vector, and sufficient amounts of plasmid DNArecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:83 from about nucleotide position 24 at least through aboutnucleotide position 449 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO83, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:83, from about nucleotide position 449 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:83 exhibit significant growth inhibition andmortality compared to controls.

Chitinase Homologous Sequences

Chitin is a β (1→4) homopolymer of N-acetylglucosamine and is found ininsect exoskeletons. Chitin is formed from UDP-N-acetlglucosamine in areaction catalyzed by chitin synthase. Chitin is a structuralhomopolymer polysaccharide, and there are many enzymatic steps involvedin the construction of this highly branched and cross-linked structure.Chitin gives shape, rigidity and support to insects and provides ascaffolding to which internal organs such as muscles are attached.Chitin must also be degraded to some extent to mediate the stepsinvolved in the insect molting process. Therefore, it is believed thatdouble stranded RNA mediated inhibition of proteins in these pathwayswould be useful as a means for controlling invertebrate pestinfestation.

Amino acid sequence information was identified from translation of cornrootworm midgut cDNA library sequences that exhibited homology tochitinase proteins. One chitinase consensus sequence (SEQ ID NO:84) wasgenerated from the alignment of two singleton EST sequences. A secondchitinase consensus sequence (SEQ ID NO:88) was generated from thealignment of four singleton sequences. Amino acid sequence translationsderived from ORF's within these sequences were annotated to a mustardbeetle (Phaedon cochleariae) chitinase amino acid sequence (GenBankAccession No. Y18011). SEQ ID NO:84 and SEQ ID NO:88 served as the basisfor constructing primer pairs for use in amplifying two sequences fromwithin the CRW genome, from CRW mRNA pools, or from cDNA sequencesderived from such mRNA pools. The nucleotide sequence of such ampliconsshould correspond to all or a part of a gene encoding a chitinasehomologous protein.

SEQ ID NO:85 and SEQ ID NO:86 correspond respectively to forward andreverse thermal amplification primers (i.e., a primer pair) for use inproducing an amplicon from nucleotide sequences derived from a cornrootworm. The sequence of such an amplicon should correspond to all or apart of a CRW gene as set forth in SEQ ID NO:84 encoding a chitinasehomologous protein. SEQ ID NO:85 and SEQ ID NO:86 each contain a 23nucleotide T7 promoter sequence from nucleotide positions 1-23respectively. Nucleotides 24-42 as set forth in SEQ ID NO:85 correspondto nucleotides 1-19 as set forth in SEQ ID NO:84. Nucleotides 24-47 asset forth in SEQ ID NO:86 correspond to the reverse complement of thesequence as set forth in SEQ ID NO:84 from nucleotides 470-493. Usingthe primer pair consisting of SEQ ID NO:85 and SEQ ID NO:86 in anamplification reaction with CRW genomic DNA as a template, a 472 basepair amplicon comprising the nucleotide sequence as set forth in SEQ IDNO:87 is produced, corresponding substantially to a part of the CRWgenome encoding a protein exhibiting homology to a chitinase protein.The nucleotide sequence as set forth in SEQ ID NO:87 from aboutnucleotide 24 through about nucleotide 516 corresponds substantially tothe nucleotide sequence as set forth at SEQ ID NO:87 from nucleotides1-493.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:87 iscloned into a plasmid vector, and sufficient amounts of plasmid DNArecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:87 from about nucleotide position 24 at least through aboutnucleotide position 516 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:87, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:87, from about nucleotide position 516 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:87 exhibit significant growth inhibition andmortality compared to controls.

SEQ ID NO:89 and SEQ ID NO:90 correspond respectively to forward andreverse genome amplification primers (i.e., a primer pair) for use inproducing an amplicon from CRW genomic DNA, CRW mRNA pools, or from cDNAsequences derived from such mRNA pools. The sequence of such an ampliconshould correspond to all or a part of a CRW gene as set forth in SEQ IDNO:88 encoding a chitinase homologous protein. SEQ ID NO:89 and SEQ IDNO:90 each contain a 23 nucleotide T7 promoter sequence from nucleotidepositions 1-23 respectively. Nucleotides 24-44 as set forth in SEQ IDNO:89 correspond to nucleotides 64-84 as set forth in SEQ ID NO:88.Nucleotides 24-44 as set forth in SEQ ID NO:90 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:88 from nucleotides779-799. Using the primer pair consisting of SEQ ID NO:89 and SEQ IDNO:90 in an amplification reaction with CRW genomic DNA as a template, a912 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:91 was produced. An alignment of the cDNA sequence as setforth in SEQ ID NO:88 and the amplicon sequence revealed that there wassubstantial dissimilarity between the two sequences, resulting only inan about 32% sequence identity. Preferably, an amplicon is producedusing primer pairs such as these as set forth at SEQ ID NO:'s 89 and 90and mRNA or cDNA as template in order to avoid such inconsistencies.

An amplicon exhibiting the sequence corresponding substantially to SEQID NO:88 is cloned into a plasmid vector, and sufficient amounts ofplasmid DNA are recovered to allow for in vitro T7 RNA polymerasetranscription from the embedded convergent T7 promoters at either end ofthe cloned amplicon. Double stranded RNA is produced and a sample issubjected to bioassay; one RNA segment, the sense strand, consisting ofthe sequence as set forth in SEQ ID NO:88 from about nucleotide position64 at least through about nucleotide position 799 except that a uridineresidue is present at each position in which a thymidine residue isshown in SEQ ID NO:88, and the reverse complement RNA segment, or theanti-sense strand, being substantially the reverse complement of thenucleotide sequence as set forth in SEQ ID NO:88, from about nucleotideposition 799 at least through about nucleotide position 64, uridinesappropriately positioned in place of thymidines. A sample of doublestranded RNA (dsRNA) is treated with DICER or with RNAse III to producesufficient quantities of small interfering RNA's (siRNA). Samplescontaining 0.15 parts per million siRNA or dsRNA are overlayed onto CRWdiet bioassay as described above and larvae are allowed to feed for 13days. CRW larvae feeding on diet containing dsRNA corresponding to allora part of the sequence as set forth at SEQ ID NO:88 exhibit significantgrowth inhibition and mortality compared to controls.

A Ubiquitin Conjugating Enzyme Homologous Sequence

The ubiquitin pathway plays an important role in the control of the cellcycle by the specific degradation of a number of regulatory proteinsincluding mitotic cyclins and inhibitors of cyclin-dependent kinasessuch as p27 of mammalian cells. Thus, genes encoding ubiquitin andassociated components may be a preferred target for double stranded RNAmediated inhibition. (Smith et al., Plant Phys. 1997, 113:281-291). Theubiquitin-dependent proteolytic pathway is one of the major routes bywhich intracellular proteins are selectively destroyed in eukaryotes.Conjugation of ubiquitin to substrate proteins is mediated by aremarkably diverse array of enzymes. Proteolytic targeting may also beregulated at steps between ubiquitination of the substrate and itsdegradation to peptides by the multi-subunit 26S protease. Thecomplexity of the ubiquitin system suggests a central role for proteinturnover in eukaryotic cell regulation, and implicates other proteins inthe pathway including ubiquitin-activating enzyme, ubiquitin-conjugatingenzyme, ubiquitin-protein ligase, and 26S proteasome subunit components.Therefore, it is believed that double stranded RNA mediated inhibitionof proteins in this pathway would be useful as a means for controllinginvertebrate pest infestation.

A CRW cDNA library sequence was identified that was predicted to encodean amino acid sequence exhibiting homology to a ubiquitin conjugatingenzyme. SEQ ID NO:92 served as the basis for constructing a primer pairfor use in producing an amplicon comprising all or a part of a ubiquitinconjugating enzyme from corn rootworm.

SEQ ID NO:93 and SEQ ID NO:94 correspond respectively to forward andreverse genome amplification primers (i.e., a primer pair) for use inproducing an amplicon from CRW genomic DNA, from CRW mRNA pools, or froma cDNA derived from such mRNA pools. The sequence of such ampliconshould correspond to all or a part of a CRW gene encoding a ubiquitinconjugating enzyme homologous protein. SEQ ID NO:93 and SEQ ID NO:94each contain a 23 nucleotide T7 promoter sequence from nucleotidepositions 1-23 respectively. Nucleotides 24-42 as set forth in SEQ IDNO:93 correspond to nucleotides 16-34 as set forth in SEQ ID NO:92.Nucleotides 24-42 as set forth in SEQ ID NO:94 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:92 from nucleotides295-313. Using the primer pair consisting of SEQ ID NO:93 and SEQ IDNO:94 in an amplification reaction with CRW genomic DNA as a template, a344 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:95 is produced, corresponding substantially to a part ofthe CRW genome encoding a protein exhibiting homology to a ubiquitinconjugating enzyme. The nucleotide sequence as set forth in SEQ ID NO:95from about nucleotide 24 through about nucleotide 321 correspondssubstantially to the nucleotide sequence as set forth at SEQ ID NO:92from nucleotides 16-313.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:95 iscloned into a plasmid vector, and sufficient amounts of plasmid DNA arerecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:95 from about nucleotide position 24 at least through aboutnucleotide position 253 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:95, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:95, from about nucleotide position 253 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse m to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth in SEQ ID NO:95 exhibit significant growth inhibition andmortality compared to controls.

A Glyceraldehyde-3-Phosphate Dehydrogenase Homologous Sequence

The glycolytic pathway is an essential pathway in most organisms and isinvolved in the production of metabolic energy from the degradation ofglucose. One important enzyme in the second stage of the glycolyticpathway is glyceraldehyde-3-phosphate dehydrogenase (G3PDH), which, inthe presence of NAD+ and inorganic phosphate, catalyzes the oxidation of3-phospho-glyceraldehyde to 3-phosphoglyceroyl-phosphate along with theformation of NADH. The important component of this reaction is thestorage of energy through the formation of NADH. Genes encoding enzymesassociated with the glycolytic pathway, and particularly genes encodingenzymes involved in the steps useful in formation of energy reserves maybe particularly useful targets for double stranded RNA mediatedinhibition in invertebrate pest species.

A CRW cDNA library sequence was identified that was predicted to encodean amino acid sequence exhibiting homology to aglyceraldehyde-3-phosphate dehydrogenase (G3PDH) protein. The consensussequence for the cluster set forth at SEQ ID NO:96 was assembled fromthe overlapping sequences of three singleton EST sequences. An aminoacid sequence translation of an ORF within the nucleotide sequence SEQID NO:96 exhibited homology with a G3PDH amino acid sequence derivedfrom a Crytococcus curvatus G3PDH gene (GenBank Accession No. AF126158)and with a G3PDH protein amino acid sequence from the organismDrosophila pseudoobscura (GenBank Accession No. AF025809). Thus, anamino acid sequence translation of the sequence as set forth at SEQ IDNO:96 was predicted to be a part of a CRW G3PDH enzyme protein. Thenucleotide sequence as set forth at SEQ ID NO:96 served as the basis forconstructing a thermal amplification primer pair for use in amplifying asequence encoding a CRW G3PDH enzyme sequence.

SEQ ID NO:97 and SEQ ID NO:98 correspond respectively to forward andreverse thermal amplification primers (i.e., a primer pair) for use inproducing an amplicon from CRW nucleotide sequences, either genome DNA,mRNA pools, or from cDNA sequences derived from such mRNA pools. Thesequence of such an amplicon should correspond to all or a part of a CRWgene encoding a G3PDH homologous protein. SEQ ID NO:97 and SEQ ID NO:98each contain a 23 nucleotide T7 promoter sequence from nucleotidepositions 1-23 respectively. Nucleotides 24-45 as set forth in SEQ IDNO:97 correspond to nucleotides 103-124 as set forth in SEQ ID NO:96.Nucleotides 24-45 as set forth in SEQ ID NO:98 correspond to the reversecomplement of the sequence as set forth in SEQ ID NO:96 from nucleotides573-594. Using the primer pair consisting of SEQ ID NO:97 and SEQ IDNO:98 in an amplification reaction with CRW genomic DNA as a template, a538 base pair amplicon comprising the nucleotide sequence as set forthin SEQ ID NO:99 is produced, corresponding substantially to a part ofthe CRW genome encoding a protein exhibiting homology to a ubiquitinconjugating enzyme. The nucleotide sequence as set forth in SEQ ID NO:99from about nucleotide 24 through about nucleotide 515 correspondssubstantially to the nucleotide sequence as set forth at SEQ ID NO:96from nucleotides 103-594.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:99 iscloned into a plasmid vector, and sufficient amounts of plasmid DNA arerecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:99 from about nucleotide position 24 at least through aboutnucleotide position 515 except that a uridine residue is present at eachposition in which a thymidine residue is shown in SEQ ID NO:99, and thereverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:99, from about nucleotide position 515 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse II to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:99 exhibit significant growth inhibition andmortality compared to controls.

A Ubiquitin B Homologous Sequence

As described above, the ubiquitin protein degradation pathway plays animportant role in the control of the cell cycle by the specificdegradation of a number of regulatory proteins including mitotic cyclinsand inhibitors of cyclin-dependent kinases such as p27 of mammaliancells. Thus, genes encoding ubiquitin and associated components may be apreferred target for double stranded RNA mediated inhibition. (Smith etal., Plant Phys. 1997, 113:281-291).

A CRW cDNA library sequence was identified that was predicted to encodean amino acid sequence exhibiting homology to a protein designatedherein as ubiquitin B. The consensus sequence for the UNIGENE clusterset forth at SEQ ID NO:100 was assembled from the overlapping sequencesof four singleton EST sequences. An amino acid sequence translation ofSEQ ID NO:100 exhibited homology with a polyubiquitin amino acidsequence from Amoeba proteus (GenBank Accession No. AF034789) and with aubiquitin protein sequence from Drosophila melanogaster (GenBankAccession No. M22428). Thus, an amino acid sequence translation of thesequence as set forth at SEQ ID NO:100 was believed to encode aubiquitin B. SEQ ID NO:100 served as the basis for constructing a primerpair for use in a thermal amplification reaction to amplify a nucleotidesequence encoding all or a part of a corn rootworm ubiquitin B aminoacid sequence.

SEQ ID NO:101 and SEQ ID NO:102 correspond respectively to forward andreverse thermal amplification primers (i.e., a primer pair) for use inproducing an amplicon from nucleotide sequences derived from CRW, eithergenomic DNA, mRNA pools, or cDNA derived from such mRNA pools. Thesequence of such an amplicon should correspond to all or a part of a CRWgene encoding a ubiquitin B homologous protein. SEQ ID NO:101 and SEQ IDNO:102 each contain a 23 nucleotide T7 promoter sequence from nucleotidepositions 1-23 respectively. Nucleotides 24-40 as set forth in SEQ IDNO:101 correspond to nucleotides 62-78 as set forth in SEQ ID NO:100.Nucleotides 24-47 as set forth in SEQ ID NO:102 correspond to thereverse complement of the sequence as set forth in SEQ ID NO:100 fromnucleotides 399-422. Using the primer pair consisting of SEQ ID NO:101and SEQ ID NO:102 in an amplification reaction with CRW genomic DNA as atemplate, a 407 base pair amplicon comprising the nucleotide sequence asset forth in SEQ ID NO:103 is produced, corresponding substantially to apart of the CRW genome encoding a protein exhibiting homology to aubiquitin conjugating enzyme. The nucleotide sequence as set forth inSEQ ID NO:103 from about nucleotide 24 through about nucleotide 384corresponds substantially to the nucleotide sequence as set forth at SEQID NO:100 from nucleotides 62-422.

The amplicon exhibiting the sequence corresponding to SEQ ID NO:103 iscloned into a plasmid vector, and sufficient amounts of plasmid DNArecovered to allow for in vitro T7 RNA polymerase transcription from theembedded convergent T7 promoters at either end of the cloned amplicon.Double stranded RNA is produced and a sample subjected to bioassay; oneRNA segment, the sense strand, consisting of the sequence as set forthin SEQ ID NO:103 from about nucleotide position 24 at least throughabout nucleotide position 384 except that a uridine residue is presentat each position in which a thymidine residue is shown in SEQ ID NO:103,and the reverse complement RNA segment, or the anti-sense strand, beingsubstantially the reverse complement of the nucleotide sequence as setforth in SEQ ID NO:103, from about nucleotide position 384 at leastthrough about nucleotide position 24, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae allowed to feed for 13 days. CRW larvae feeding on dietcontaining dsRNA corresponding to all or a part of the sequence as setforth at SEQ ID NO:103 exhibit significant growth inhibition andmortality compared to controls.

A Juvenile Hormone Esterase Homolog

As indicated above, insect juvenile hormone controls and regulates avariety of necessary biological processes within the insect life cycleincluding but not necessarily limited to metamorphosis, reproduction,and diapause. Disruption of JH synthesis or degradation pathways usinggene suppression technology could be an effective target for doublestranded RNA mediated pest inhibition.

An insect juvenile hormone esterase homologous sequence derived from CRWwas identified for use in the present invention. SEQ ID NO:104corresponds substantially to a CRW midgut cDNA nucleotide sequence. Anamino acid sequence translation of SEQ ID NO:104 predicted homology to ajuvenile hormone esterase (JHE). SEQ ID NO:105 and SEQ ID NO:106correspond respectively to forward and reverse amplification primers(i.e., a primer pair) for use in producing an amplicon from CRW genomicDNA, CRW mRNA pools, or a CRW cDNA derived from such pools. The sequenceof such an amplicon should correspond to all or a part of a CRW geneencoding a JHE homologous protein. SEQ ID NO:105 and SEQ ID NO:106 eachcontain a 23 nucleotide T7 promoter sequence from nucleotide positions1-23 respectively. Nucleotides 24-45 as set forth in SEQ ID NO:105correspond to nucleotides 58-79 as set forth in SEQ ID NO:104.Nucleotides 24-46 as set forth in SEQ ID NO:106 correspond to thereverse complement of the sequence as set forth in SEQ ID NO:104 fromnucleotides 338-360. Using the primer pair consisting of SEQ ID NO:105and SEQ ID NO:106 in an amplification reaction with CRW genomic DNA as atemplate, a 348 base pair amplicon wqas produced comprising thenucleotide sequence as set forth in SEQ ID NO:186 or in SEQ ID NO:15through SEQ ID NO:108. Preferably, an amplicon is produced using a CRWmRNA pool or a cDNA derived from such pool as the template nucleotidesequence in the amplification reaction.

An amplicon exhibiting the sequence corresponding to SEQ ID NO:186 or inSEQ ID NO:15 through SEQ ID NO:108 is cloned into a plasmid vector, andsufficient amounts of plasmid DNA are recovered to allow for in vitro T7RNA polymerase transcription from the embedded convergent T7 promotersat either end of the cloned amplicon. Double stranded RNA is producedand a sample is subjected to bioassay; one RNA segment, the sensestrand, consisting of the sequence as set forth in SEQ ID NO:186 or inSEQ ID NO:15 through SEQ ID NO:108 from about nucleotide position 45 atleast through about nucleotide position 302 except that a uridineresidue is present at each position in which a thymidine residue isshown in SEQ ID NO:107, and the reverse complement RNA segment, or theanti-sense strand, being substantially the reverse complement of thenucleotide sequence as set forth in SEQ ID NO:186 or in SEQ ID NO:15through SEQ ID NO:108 from about nucleotide position 302 at leastthrough about nucleotide position 45, uridines appropriately positionedin place of thymidines. A sample of double stranded RNA (dsRNA) istreated with DICER or with RNAse III to produce sufficient quantities ofsmall interfering RNA's (siRNA). Samples containing 0.15 parts permillion siRNA or dsRNA are overlayed onto CRW diet bioassay as describedabove and larvae are allowed to feed for 13 days. CRW larvae feeding ondiet containing dsRNA corresponding to all or a part of the sequence asset forth at SEQ ID NO:186 or in SEQ ID NO:15 through SEQ ID NO:108exhibit significant growth inhibition and mortality compared tocontrols.

Ten of the double stranded RNA molecules listed above were tested inbioassay in parallel with small interfering RNA's generated from thedouble stranded RNA molecules. Double stranded RNA sequence samples orsmall interfering RNA samples prepared from the double stranded RNAsequence samples, each corresponding to amino acid sequences annotatedto selected target gene homologs including a 40 kDa V-ATPase homolog, anEF-1-alpha homolog, a 26S proteasome subunit p28 homolog, a juvenilehormone epoxide hydrolase homolog, a CHD3 homolog, a beta-tubulinhomolog, two chitinase homologs, a transcription factor IIB homolog, anda juvenile hormone esterase homolog (corresponding respectively to SEQID NO:46, SEQ ID NO:50, SEQ ID NO:58, SEQ ID NO:63, SEQ ID NO:18, SEQ IDNO:32, SEQ ID NO:87, SEQ ID NO:91, SEQ ID NO:83, and SEQ ID NO:107) wereapplied to the insect diet at a concentration of about ten parts permillion (30 microliters of solution containing a double stranded RNAsample adjusted to an appropriate concentration was added to microtiterdish wells containing 200 microliters insect diet per well). A total ofeighteen wells were used for each sample. A single first instar larvawas added to each well after the RNA samples had diffused into the diet.The bioassays were incubated as indicated above for about 13 days andmonitored daily for morbidity and mortality. An amino acid sequencevariant Cry3Bb1 insecticidal crystal protein designated as insecticidalprotein 11231 in English et al. (U.S. Pat. No. 6,642,030) was used as apositive control for observing insecticidal bioactivity specific for therootworm pest. Cry3Bb was applied to the diet as set forth in English etal., except that the concentration of Cry3Bb in the diet was adjusted tobe about 200-300 parts per million. A separate control sample that wastreated only with buffer or water was also included in the assay. Adouble stranded RNA control sample and a small interfering RNA controlsample produced from double stranded RNA control samples were alsoincluded as additional negative controls (MEGAscript® RNAi Kit, AMBION,Austin, Tex.).

An initial evaluation using double stranded RNA molecules derived fromthese ten sequences indicated that larvae which were allowed to feed ondiet containing double stranded RNA corresponding to a 40 kDa V-ATPasehomolog (SEQ ID NO:46), a CHD3 homolog (SEQ ID NO:18), and abeta-tubulin homolog (SEQ ID NO:42) exhibited significant mortality incomparison to the controls. Based on these results, additional bioassayswere conducted to test whether small interfering double stranded RNAparticles would be more effective than the full length double strandedRNA molecules.

A Alpha Tubuliln Homologous Sequence

Eukaryotic cells generally utilize cytoskeletal structural elements thatare important, no t only as a mechanical scaffold, but also insustanining the shape of the cell. Semiflexible microfilaments makecells mobile, help them to divide in mitosis (cytokinesis) and, invertebrate and invertebrate animals, are responsible for muscularcontraction. The relatively stiff microtubules which are made up ofalpha and beta tubulin proteins play an important role in acting as asort of highway for transport of vesicles and organelles and in theseparation of chromosomes during mitosis (karyokinesis). The flexibleintermediate filaments provide at least additional strength to theoverall cellular structure. The cytoskeleton is also known to beinvolved in signaling across the cell cytoplasm. Taking these functionsinto account, it is believed that any disruption of the cytoskeleton oreven subtle changes of its integrity may cause pathological consequencesto a cell.

At least one CRW cDNA library sequence was identified that was predictedto encode an amino acid sequence exhibiting homology to a proteindesignated herein as alpha tubulin, and more specifically referred toherein as SEQ ID NO:185 as set forth in the sequence listing. An aminoacid sequence translation of the sequence as set forth at SEQ ID NO:185was believed to encode an alpha tubulin protein or fragment thereof. SEQID NO:185 served as the basis for constructing a sequence that ispredicted to form a double stranded RNA when expressed in E. coli from aT7 promoter or in a plant from a plant functional promoter. A sequenceserving as the basis for such double stranded RNA coding sequence is SEQID NO:108 as set forth in the sequence listing from nucleotide position58 through nucleotide position 1010. This sequence can be expressed as aRNA molecule and purified and tested in vitro feeding assays fordetermining corn rootworm inhibition.

A T7 RNA polymerase promoter was introduced upstream of a nucleotidesequence as set forth in SEQ ID NO:108 from nucleotide position 58through nucleotide position 1010, and RNA was produced from thisconstruct (pIC17527). Such RNA was tested in triplicate in an in vitrofeeding assay against corn rootworms against a beta tubulin positivecontrol (described hereinabove), 200 ppm Cry3Bb, and an untreatedcontrol, and mean mortality was determined. Untreated control samplesexhibited less than about 3-5% mortality, while all other test samplesexhibited from about 20 to about 55% mortality. Cry3Bb samples exhibitedfrom about 20 to about 36% mortality, while the pIC17527 samples (at 15ppm) exhibited from about 38 to about 45% mortality. The D8 (betatubulin as set forth herein above) samples, also at about 15 ppm,exhibited from about 38 to about 52% mortality. Based on these results,the alpha tubulin construct was placed under the control of a plantfunctional promoter, used to transform corn plants, and transformationevents arising from the transformation were tested for their ability toresist corn rootworm infestation.

Roots from R0 corn plants transformed with a nucleotide sequence as setforth in SEQ ID NO:108. Briefly, the sequence encoding a dsRNA constructin SEQ ID NO:108 as described above was linked at the 5′ end to asequence that consisted of an e35S promoter operably linked to a maizehsp70 intron and at the 3′ end to a NOS3′ transcription termination andpolyadenylation sequence. This expression cassette was placed downstreamof a glyphosate selection cassette. These linked cassettes were thenplaced into an Agrobacterium tumefaciens plant transformation functionalvector and the new vector was designated as pMON72829 (the alpha tubulindsRNA construct), used to transform maize tissue to glyphosatetolerance, and events were selected and transferred to soil. R0 plantroots were fed to western corn rootworm larvae (WCR, Diabroticavirifera). Transgenic corn roots were handed-off in Petri dishes withMSOD medium containing the antibiotics and glyphosate for in vitroselection. Two WCR larvae were infested per root in each dish with afine tip paint brush. The dishes were sealed with Parafilm to preventthe larvae from escaping. The assays were placed into a 27° C., 60% RHPercival incubator in complete darkness. Contamination and larvalquality were monitored. After six days of feeding on root tissue, thelarvae were transferred to WCR diet in a 96 well plate. The larvae wereallowed to feed on the diet for eight days making the full assayfourteen days long. Larval mass and survivorship were recorded foranalysis. A one-way analysis was performed on the larval mass data and aDunnett's test to look for statistical significance compared to LH244,an untransformed negative control. WCR larvae were significantly stunted(a=0.05) after feeding on two events, ZM_S125922 and ZM_S125938, andcompared to growth of larvae fed on negative control plants (p<0.02).Larvae feeding on negative control plants exhibited a mean larval massof from about 0.6 to about 0.8 mg, while larvae feeding on thetransgenic roots exhibited a mean larval mass of from about 0.1 to about0.2 mg.

Transgenic corn plants (R0) generated using pMON72829 were planted into10 inch pots containing Metromix soil after reaching an appropriatesize. When plants reached the V4 growth stage, approximately 1000Western corn rootworm (WCR, Diabrotica virifera) eggs were infested intothe root zone. Non-transgenic corn of the same genotype was infested ata similar growth stage to serve as a negative control. Eggs werepre-incubated so hatch would occur within 24 hours of infestation.Larvae were allowed to feed on the root systems for 3 weeks. Plants wereremoved from the soil and washed so that the roots could be evaluatedfor larval feeding. Root damage was rated using a Node Injury Scale(NIS) was used to score the level of damage where a 0 indicates nodamage, a 1 indicates that one node of roots was pruned to within 1.5inches, a 2 indicates that 2 nodes were pruned, while a 3 indicates that3 nodes were pruned. Because the plants being used for evaluation weredirectly out of tissue culture after transformation and becausetransformation events are unique, only a single plant was evaluated perevent at this time and no statistics are available. All plants in theassay presented symptoms of larval feeding indicating that a successfulinfestation was obtained. Negative control plant roots were moderatelyto severely damaged averaging about 1.9 on the Node Injury Scale. Asingle plant from eight different transgenic events was tested. Roots ofthree of these transgenic plants provided excellent control of larvalfeeding, averaging about 0.2 or less on the Node Injury Scale. Rootsfrom two of the transgenic plants exhibited moderate feeding damage, andthree other transgenic plants exhibited no control of larval feeding.This data indicated that the double nucleotide sequence encoding a RNAsequence that can form into a dsRNA is fully capable of providingprotection from rootworm pest infestation when expressed in a transgenicplant and that plant is provided in the diet of the rootworm pest.

Several additional cDNA sequences from CRW libraries were produced forexpression as dsRNA based on the homology of the protein predicted to beexpressed from the cDNA corresponding to an essential protein, essentialfunction, or essential gene. For example, various portions of SEQ IDNO:'s 47, 55, 59, 64, 68, 72, 76 were each expressed and used separatelyas dsRNA samples and tested in bioassay. Bioassay results indicated thatthese sequences did not result in a consistent obsrervable mortality orreduced larval mass in comparison to untreated controls, and thesesequences were thus not tested further. One explanation for the lack ofobservable mortality or other effects could be that, for these genes,there are expressed homologues present within the population of genesencoding proteins that have similar functions but exhibit sufficientsequence differences that the RNAi pathway does not act to suppress thehomologue using the single sequence selected for suppression.

Example 3

This example illustrates significant pest inhibition obtained by feedingto an invertebrate pest a diet containing double stranded RNA sequencesderived from that pest.

Artificial diet sufficient for rearing corn rootworm larvae was preparedby applying samples of double stranded RNA sequences derived from sixdifferent corn rootworm cDNA library sequences. Corn rootworm larvaewere allowed to feed on the diet for several days and mortality,morbidity and stunting monitored in comparison to rootworms allowed tofeed only on control diet. The nucleotide sequences that were used inthe diet were derived from sequences as set forth in SEQ ID NO:46, SEQID NO:50, SEQ ID NO:58, SEQ ID NO:63, SEQ ID NO:18, and SEQ ID NO:42,each corresponding to nucleotide sequences derived from a corn rootwormcDNA library, the deduced amino acid sequence translation of whichcorresponds respectively to proteins annotated to a 40 kDa V-ATP-asehomolog, an EF1α homolog, a 26S proteasome subunit homolog, a juvenilehormone epoxide hydroxylase homolog, a CHD3 homolog, and a β-tubulinhomolog.

Double stranded RNA's (dsRNA's) corresponding to these sequences wereproduced as indicated above. siRNA's were generated by cleavage of thecorresponding dsRNA's using RNAse III enzyme, which is known to cleavedsRNA into 12-15 bp dsRNA fragments containing 2 to 3 nucleotide 3′overhangs, and 5′ phosphate and 3′ hydroxyl termini. The siRNA'sproduced in this fashion were expected to exhibit the same properties assiRNA's that would be produced by the Dicer enzyme involved in theeukaryotic RNAi pathway. The dsRNA's and siRNA's were sampled onto theCRW diet as indicated above at about 0.15 ppm. 12 individual cornrootworm larvae were tested separately against each dsRNA or siRNAsample as indicated above and the results were scored after 13 days.

A significant reduction in larval mass (p<0.05) was observed for larvaefeeding on diet containing 0.15 ppm dsRNA sequences as set forth in SEQID NO:46, SEQ ID NO:63, SEQ ID NO:18, and SEQ ID NO:42 compared to theuntreated control (UTC). siRNA corresponding to sequences as set forthin SEQ ID NO:46, SEQ ID NO:50, SEQ ID NO:58, and SEQ ID NO:18 alsoprovided a significant reduction in larval mass (p<0.05). However, thelarval sample size was insufficient to establish with certainty that thedsRNA or siRNA molecules which resulted in the greatest decrease inlarval mass compared to the controls was a result of random variation orclearly a result based on double stranded RNA mediated inhibition ofsome biological function within the rootworm larvae. Therefore, based onthese results, RNA sequences corresponding to SEQ ID NO:46, SEQ IDNO:50, SEQ ID NO:18, and SEQ ID NO:42 were re-evaluated with a largerlarval sample size. dsRNA or siRNA samples were applied to each of 72wells for each of the four RNA sequences in the evaluation. Each wellwas loaded with 0.15 ppm dsRNA or siRNA as indicated above by applying a30 microliter volume containing the RNA to the surface of the diet andallowing the sample to infuse and the surface of the diet to dry. Asingle larva was added to each well and incubated for thirteen days.Larval mortality and morbidity were evaluated, and mass of survivinglarvae was determined. The bioassay results are shown in Table 1. TABLE1 Bioassay Results siRNA (SEQ ID NO) % Mortality Mass (mg) STE dsRNABioassay Results 46 62.25 0.42 0.12 50 50.5 0.39 0.05 18 47.67 0.37 0.0542 92.24 0.27 0.05 dsRNA Control¹ 21.08 0.58 0.08 Cry3Bb² 42.08 0.210.03 UTC 5.58 1.24 0.33 siRNA Bioassay Results 46 21.11 0.45 0.06 4621.39 1.31 0.16 18 15.83 0.73 0.09 42 20.00 0.39 0.07 siRNA Control¹6.52 1.10 0.16 Cry3Bb² 27.78 0.49 0.05 UTC 9.45 1.25 0.18All siRNA samples at 0.15 ppm per wellUTC - 10 mM TrisHCl pH 7.5STE - standard error¹phage λ dsRNA, EPICENTER TECHNOLOGIES, Madison, Wisconsin in dsRNAbioassay; MEGAscript ® RNAi Kit, AMBION, Austin, Texas in siRNA bioassay²Cry3Bb variant 11231 at 300 ppm in dsRNA bioassay, 200 ppm in siRNAbioassay

All samples were compared to each other using Tukey's HSD method ratherthan to any single control. Significant larval stunting was observed foreach dsRNA or siRNA tested as judged by average mass reduction ofsurviving larvae compared to the untreated control. More importantly,the double stranded small interfering RNA samples demonstrated anability to cause mortality and morbidity (based on reduced larval mass)at a level that was at least as effective as the positive control sampleCry3Bb variant 11231. These results suggest that any double stranded RNAmolecule derived from a messenger RNA sequence present in the cells ofcorn rootworm could be effective when provided to rootworms in theirdiet to inhibit rootworm pest infestation of a plant species.

Example 4

The example illustrates nucleotide sequences for expression in a plantcell, and the effect of providing such nucleotide sequences in the dietof a corn rootworm.

A CHD3 coding sequence derived from a corn rootworm cDNA library wasused to construct a nucleotide sequence encoding a stabilized doublestranded RNA. A cDNA sequence as set forth in SEQ ID NO:18 encoding apart of an ortholog or a homolog of a CHD3 amino acid sequence was usedto construct a primer pair for use in a thermal amplification reactionusing corn rootworm genomic template DNA. The primer pair as set forthat SEQ ID NO:16 and SEQ ID NO:17 enabled the amplification of a doublestranded genome amplicon, one strand of which exhibited the sequence asset forth in SEQ ID NO:18. Three nucleotide sequence segments wereproduced from the nucleotide sequence as set forth in SEQ ID NO:18. Afirst nucleotide segment (SEQ ID NO:190) was produced using a nucleotidesequence as set forth in SEQ ID NO:18 as template in a thermalamplification reaction along with the thermal amplification primer pairexhibiting the sequences as set forth in SEQ ID NO:19 and SEQ ID NO:20.A second nucleotide segment (SEQ ID NO:24) was produced using anucleotide sequence as set forth in SEQ ID NO:18 as template in athermal amplification reaction along with the thermal amplificationprimer pair exhibiting the sequences as set forth in SEQ ID NO:22 andSEQ ID NO:23. A third nucleotide segment (SEQ ID NO:27) was producedusing a nucleotide sequence as set forth in SEQ ID NO:18 as template ina thermal amplification reaction along with the thermal amplificationprimer pair exhibiting the sequences a set forth in SEQ ID NO:25 and SEQID NO:26. The 3′ end of one of the strands the first segment iscomplementary to the 3′ end of one of the strands of the second segmentso that in a thermal amplification reaction containing both of thesesegments, these complementary ends hybridize and allow for thepolymerase-mediated extension of both strands from their respective 3′ends. The 3′ end of the other strand of the second segment iscomplementary to the 3′ end of one of the strands of the third segment,so that in a thermal amplification reaction containing both of thesesegments, these complementary ends hybridize and allow for thepolymerase-mediated extension of both strands from their respective 3′ends. In a thermal amplification reaction containing all three segmentsand their complementary sequences, i.e., the first, the second and thethird segment, along with thermal amplification primer sequences as setforth in SEQ ID NO:19 and SEQ ID NO:26, a new sequence is produced asset forth in SEQ ID NO:28, that when placed under the control of apromoter that functions in plants, can produce an RNA nucleotidesequence substantially identical to the sequence as set forth in SEQ IDNO:28 except that uridine residues are present in place of thymidineresidues. This RNA nucleotide sequence can form into a stabilized RNAmolecule by virtue of the reverse complementarity of the third segmentto the first segment, in which the portion of SEQ ID NO:28 correspondingto the third segment from about nucleotide position 303 to aboutnucleotide position 473 hybridizes to the portion of SEQ ID NO:28corresponding to the first segment from about nucleotide position 1through about nucleotide position 171, and the first and the thirdsegments are linked by a second nucleotide sequence segment, which inthis example is represented by the portion of SEQ ID NO:28 correspondingto the second segment from about nucleotide position 172 through aboutnucleotide position 302. Expression of a nucleotide sequencecorresponding to SEQ ID NO:28 in plant cells results in the synthesis ofa stabilized RNA molecule. Plant cells transcribing a nucleotidesequence as set forth in SEQ ID NO:28 into an RNA sequence can beprovided in the diet of a corn rootworm. A corn rootworm feeding uponsuch plant cells stop feeding, is prevented from developing into anadult beetle, is prevented from breeding, dies, or suffers from any orall of these effects as a result of inhibition of the CHD3 homologousprotein synthesis.

A β-tubulin coding sequence derived from a corn rootworm cDNA librarywas used to construct a nucleotide sequence encoding a stabilized doublestranded RNA. A cDNA sequence as set forth in SEQ ID NO:29 encoding apart of an ortholog or a homolog of a β-tubulin amino acid sequence wasused to construct a primer pair for use in a thermal amplificationreaction using corn rootworm genomic template DNA. The primer pair asset forth at SEQ ID NO:30 and SEQ ID NO:31 enabled the amplification ofa double stranded genome amplicon, one strand of which exhibited thesequence as set forth in SEQ ID NO:32. Three nucleotide sequencesegments were produced from the nucleotide sequence as set forth in SEQID NO:32. A first nucleotide segment (SEQ ID NO:189) was produced usinga nucleotide sequence as set forth in SEQ ID NO:32 as template in athermal amplification reaction along with the thermal amplificationprimer pair exhibiting the sequences as set forth in SEQ ID NO:33 andSEQ ID NO:34. A second nucleotide segment (SEQ ID NO:38) was producedusing a nucleotide sequence as set forth in SEQ ID NO:32 as template ina thermal amplification reaction along with the thermal amplificationprimer pair exhibiting the sequences as set forth in SEQ ID NO:36 andSEQ ID NO:37. A third nucleotide segment (SEQ ID NO:41) was producedusing a nucleotide sequence as set forth in SEQ ID NO:32 as template ina thermal amplification reaction along with the thermal amplificationprimer pair exhibiting the sequences a set forth in SEQ ID NO:39 and SEQID NO:40. The 3′ end of one of the strands the first segment iscomplementary to the 3′ end of one of the strands of the second segmentso that in a thermal amplification reaction containing both of thesesegments, these complementary ends hybridize and allow for thepolymerase-mediated extension of both strands from their respective 3′ends. The 3′ end of the other strand of the second segment iscomplementary to the 3′ end of one of the strands of the third segment,so that in a thermal amplification reaction containing both of thesesegments, these complementary ends hybridize and allow for thepolymerase-mediated extension of both strands from their respective 3′ends. In a thermal amplification reaction containing all three segmentsand their complementary sequences, i.e., the first, the second and thethird segment, along with thermal amplification primer sequences as setforth in SEQ ID NO:33 and SEQ ID NO:40, a new sequence is produced asset forth in SEQ ID NO:42, that when placed under the control of apromoter that functions in plants, can produce an RNA nucleotidesequence substantially identical to the sequence as set forth in SEQ IDNO:42 except that uridine residues are present in place of thymidineresidues. This RNA nucleotide sequence can form into a stabilized RNAmolecule by virtue of the reverse complementarity of the third segmentto the first segment, in which the portion of SEQ ID NO:42 correspondingto the third segment from about nucleotide position 358 to aboutnucleotide position 577 hybridizes to the portion of SEQ ID NO:42corresponding to the first segment from about nucleotide position 31through about nucleotide position 250, and the first and third segmentsare linked by a second nucleotide sequence segment, which in thisexample is represented a portion of SEQ ID NO:42 corresponding to thesecond segment from about nucleotide position 251 through aboutnucleotide position 357. Expression of a nucleotide sequencecorresponding to SEQ ID NO:42 in plant cells results in the synthesis ofa stabilized RNA molecule. Plant cells transcribing a nucleotidesequence as set forth in SEQ ID NO:42 into an RNA sequence can beprovided in the diet of a corn rootworm. A corn rootworm feeding uponsuch plant cells stop feeding, is prevented from developing into anadult beetle, is prevented from breeding, dies, or suffers from any orall of these effects as a result of inhibition of the β tubulin proteinsynthesis.

Example 5

This example illustrates the synergistic effects of providing in thediet of an invertebrate pest one or more pesticidally effectivecompositions together with one or more double stranded RNA sequencesderived from the invertebrate pest, the one or more dsRNA sequenceshaving previously demonstrated a pesticidal effect when provided in thediet of the pest.

As indicated in example 3, providing in the diet of an invertebrate pesta double stranded RNA molecule derived from that pest results in theinhibition of one or more biological functions in the pest and thereforefunctions to achieve a pesticidal effect, resulting in the mortality ofthe pest or some other measurable feature that reduces the ability ofthe pest to infest a particular environment or host. The addition of oneor more other pesticidal agents, each different from each other and eachfunctioning to achieve its pesticidal effect by a means different fromthe way in which the dsRNA functions to achieve its pesticidal effect,may result in achieving an improvement in the level of pest control andwould further decrease the likelihood that the pest would developresistance to any one or more of the pesticidal agents or dsRNA's whenused alone to achieve inhibition of the pest.

To test this, CRW larvae are allowed to feed on diet into which isincorporated varying amounts of a Cry3Bb rootworm inhibitory protein anda fixed amount of a double stranded RNA formulated above as set forth inExample 2 or 3, such as a dsRNA corresponding to SEQ ID NO:28 or SEQ IDNO:42. A synergistic pest inhibition effect is observed. As set forth inExample 2 and 3, an LD50 amount of a variant Cry3Bb was used to achieveabout 50% insect larvae mortality with a coordinate reduction in fitnessof the surviving larvae as judged by the reduced larvae weights incomparison to negative controls. Reducing the amount of the insecticidalprotein in the diet results in a coordinate reduction in the mortalityrate, and an increase in the mean surviving larval weights. The additionof dsRNA corresponding to either SEQ ID NO:42 or to SEQ ID NO:28 resultsin almost complete mortality at each concentration of Cry3Bb, and asubstantial decrease in the mean weight of any survivors. This suggestsa synergistic effect. Synergy may be achieved through the disturbance inthe larval mid-gut as a result of the introduction of any amount ofCry3Bb, which has been shown to introduce pores into the mid-gutmembrane. The may pores allow a greater level of the double stranded RNAspecies to permeate into cells or even into the haemolymph, resulting ina more efficient delivery of the dsRNA species into the larvae, and thusresulting in a more efficient reduction in the suppression of the targetmRNA. Particular combinations of pore forming compositions along withdouble stranded RNA compositions results in an enhanced and synergisticpesticidal effect because dsRNA is now more able to be distributedthroughout the haemolymph and exert effects on cells and tissues remotefrom the gut of the pest.

Example 6

This example illustrates how the nucleotide sequence fragments of theV-ATPase, when provided in the double stranded RNA form in the diet of aCRW species, are useful for controlling the insect pest.

The sequence as set forth in SEQ ID NO:115 is a cDNA clone thatrepresents 1870 base of an approximately 2400 base pair mRNA having asubstantial sequence identity to a Drosophila melanogaster VacuolarATPase (68 kd, subunit 2). This cDNA clone was fully sequenced on bothstrands using primers designed from the initial sequence data. Thesesequencing primers were listed as SEQ ID NO:116 through SEQ ID NO:131.SEQ ID NO:132 and SEQ ID NO:133 were sequences of the primers used toproduce a copy of SEQ ID NO:115 from the cloning vector pSPORT(Invitrogen). Each primer contained a 20-nucleotide T7 promoter sequencefrom nucleotide positions 1-20. Nucleotides 21-44 set forth in SEQ IDNO:132 and nucleotides 21-45 of SEQ ID NO:133 corresponded to the pSPORTvector (Invitrogen). These primers resulted in a DNA template with theT7 promoters at either end, allowing for the in vitro production ofdouble stranded RNA with a T7 RNA polymerase. When double stranded RNAderived from SEQ ID NO:115 was included in the CRW diet about 80%mortality was observed in CRW.

Six different regions of SEQ ID NO:115 were tested by using thefollowing sets of amplification primers: SEQ ID NO:134 and SEQ IDNO:135, corresponding to nucleotides 1 to 291 (known as section #1, 271base pairs) of SEQ ID NO:115; SEQ ID NO:136 and SEQ ID NO:137corresponding to nucleotides 292 to 548 (known as section #2, 260 basepairs); SEQ ID NO:138 and SEQ ID NO:139 corresponding to 549 to 830(known as section #3, 271 base pairs); SEQ ID NO:140 and SEQ ID NO:141corresponding to nucleotides 840 to 1345 (known as section #4, 505 basepairs); SEQ ID NO:142 and SEQ ID NO:143 corresponding to nucleotides1360 to 1621 (known as section #5 261 base pairs); SEQ ID NO:144 and SEQID NO:147 corresponding to nucleotides 1540 to 1870 (known as section#6, 278 base pairs) (See FIG. 1 for the locations and sizes). Note thatsection 5 and 6 overlapped by approximately 80 base pairs. When these 6sections were separately incorporated into CRW diet sections #1, #2, #3and #4 showed CRW mortality ranging from 94% to 100%. Section #5 and #6showed no CRW mortality above the background seen in the untreatedcontrols (see FIG. 2A). The sequence contained in section #1 was furthersubdivided into 3 smaller sections. When these samples were tested inthe CRW bioassay, mortality between 80 and 90% was observed.

A second means for testing the bioactivity of dsRNA molecules derivedfrom CRW genes is to construct a self-complementary RNA molecule. Bycombining the same DNA sequence in the reverse orientation with the T7RNA polymerase promoter a single RNA molecule can be synthesized whichis self complementary. One such a RNA molecule was constructed bycombining the nucleotides 1 through 345 with the nucleotides 50 through325, from the nucleotide sequence as set forth in SEQ ID NO:115. Theresulting sequence is as set forth in SEQ ID NO:148 and was designatedas pIC17527. pIC17527 was cloned into pTOPT2.1 (Invitrogen). Using theT7 promoter in the pTOPO 2.1 vector a dsRNA approximately 500 base pairnucleotides was produced and incorporated into CRW diet. The resultingmortality was between 80% to 100%.

Example 7

This example illustrates the oral toxicity of dsRNAs towards larvae ofthe Colorado Potato Beetle, Leptinotarsa decemlineata.

Total RNA was isolated from larvae of the Colorado potato beetle (CPB),Leptinotarsa decemlineata, using the Ambion mirVana kit (Catalog # 1560)and recommended procedures (Ambion Inc., Austin, Tex.). CPB larvaeoccupying approximately 200 μL volume in a microfuge tube were used foreach preparation. Five micrograms of total RNA were used to prepare cDNAusing the Invitrogen Thermoscript™ RT-PCR system (Catalog # 11146) andrecommended procedures for random primer-mediated cDNA synthesis(Invitrogen, Carlsbad, Calif.). This cDNA was used as a template foramplification of V-ATPase A subunit 2 ortholog sequences using Taq DNApolymerase and the oligonucleotide primers pr 550 (SEQ ID NO:171) andpr552 (SEQ ID NO:172). These primers were designed by aligning thenucleotide sequences for the nearest V-ATPase A orthologs from Manducasexta (SEQ ID NO:162), Aedes aegypti (SEQ ID NO:163), Drosophilamelanogaster (SEQ ID NO:164), and Diabrotica virgifera (WCR) andselecting regions of minimal degeneracy. Primer pr550 corresponds tonucleotides 230-252 in the M. sexta gene sequence while primer pr552corresponds to nucleotides 1354-1331 in the M. sexta gene sequence.

Amplification was achieved using a touchdown amplification procedurewith the following cycling parameters:

-   Step 1. 94 C, 2 min;-   Step 2. 94 C, 30 sec;-   Step 3.50 C, 2 min;-   Step 4. 72 C, 2 min-   (35 cycles for steps 2-4, with a step down of −0.3 C per cycle for    step 3);-   Step 5. 72 C, 10 min; and-   Step 6.4 C.

The approximately 1.2 kb DNA fragment amplified from the cDNA was clonedinto the vector pCR2.1-TOPO (Invitrogen) to yield the recombinantplasmid pIC17105. The nucleotide sequence of the cloned insert (SEQ IDNO:155) shares only 82% nucleotide sequence identity with the V-ATPase Asubunit 2 ortholog sequence from the Western corn rootworm, Diabroticavirgifera, however, the deduced amino acid sequences for the encodedV-ATPase A proteins share 97% sequence identity.

The V-ATPase A ortholog sequence in plasmid pIC17105 was amplified usingprimers pr568 (SEQ ID NO:173) and pr569 (SEQ ID NO:174), designed as“universal” primers for generating DNA templates with flanking T7polymerase promoter sequences from pCR2.1-TOPO clones. The amplified DNAserved as the template for dsRNA synthesis using the Ambion MEGAscript™kit (Catalog # 1626) and recommended procedures (Ambion Inc., Austin,Tex.). Purified dsRNA derived from the L. decemlineata V-ATPase Aortholog sequence was fed to larvae of L decemlineata in an insectfeeding assay.

The CPB diet consists of 13.2 g/L agar (Serva 11393), 140.3 g/LBio-Serve pre-mix (F9380B), 5 ml/L KOH (18.3% w/w), and 1.25 ml/Lformalin (37%). The diet was dispensed in 200 uL aliquots onto 96-wellplates and dried briefly prior to sample application. Twenty μL of testsample were applied per well, with sterile water serving as theuntreated check (UTC). Plates were allowed to dry before adding insectlarvae. One neonate CPB larva was added per well with a fine paintbrush.Plates were sealed with mylar and ventilated using an insect pin. Fortylarvae were tested per treatment. The bioassay plates were incubated at27 C, 60% RH, in complete darkness for 10-12 days. The plates werescored for larval stunting and mortality. Data were analyzed using JMP®4 statistical software (SAS Institute, Cary, N.C., USA). TABLE 2 Oraltoxicity of dsRNA to CPB larvae Treatment % Mortality Std Dev SEM 95% CIUntreated check 8.33 10.21 4.17 −2.38-19.04 V-ATPase A dsRNA 87.5 10.833.61 79.18-95.82

Example 8

This example illustrates the oral toxicity of dsRNAs towardslepidopteran larvae.

Total RNA was isolated from 2^(nd)-3^(rd) instar larvae of Spodopterafnrgiperda, Helicoverpa zea, Agrotis ipsilon, and Ostrinia nubilalisusing the Ambion mirVana kit (Catalog # 1560) and recommended procedures(Ambion Inc., Austin, Tex.). Larvae occupying approximately 200 μLvolume in a microfuge tube were used for each preparation.

Five micrograms of total RNA were used to prepare cDNA using theInvitrogen Thermoscript™ RT-PCR system (Catalog # 11146) and recommendedprocedures for random primer-mediated cDNA synthesis (Invitrogen,Carlsbad, Calif.). This cDNA was used as a template for amplification ofV-ATPase A subunit 2 ortholog sequences using Taq DNA polymerase and theoligonucleotide primers pr 550 (SEQ ID NO:171) and pr552 (SEQ IDNO:172).

These primers were designed by aligning the nucleotide sequences for thenearest V-ATPase A orthologs from Manduca sexta, Aedes aegypti,Drosophila melanogaster, and Diabrotica virgifera (WCR) and selectingregions of minimal degeneracy. Primer pr550 corresponds to nucleotides230-252 in the M. sexta gene sequence while primer pr552 corresponds tonucleotides 1354-1331 in the M. sexta gene sequence.

Amplification was achieved using a touchdown PCR procedure with thecycling parameters as described in Example 7. The amplified DNA productswere cloned into pCR2.1-TOPO and sequenced to confirm their identity.The recombinant plasmids containing the ortholog gene sequences arelisted in Table 3. TABLE 3 Lepidopteran V-ATPase A subunit 2 orthologsequences Plasmid Insect species SEQ ID NO. pIC17088 Spodopterafrugiperda SEQ ID NO: 156 pIC17101 Agrotis ipsilon SEQ ID NO: 157pIC17102 Helicoverpa zea SEQ ID NO: 158 pIC17103 Ostrinia nubilalis SEQID NO: 159

The V-ATPase A ortholog sequences in plasmids pIC17088, pIC17101,pIC17102 were amplified using primers pr555 (SEQ ID NO:175) and pr556(SEQ ID NO:176), designed to generate DNA fragments with flanking andopposing T7 polymerase promoters for in vitro dsRNA synthesis.

Double-stranded RNAs (dsRNAs) for the FAW, BCW, and CEW orthologsequences were synthesized from these amplified DNA templates using theAmbion MEGAscript™ kit (Catalog # 1626) and recommended procedures(Ambion Inc., Austin, Tex.) and submitted for insect bioassays at 10ppm.

For these assays, artificial lepidopteran diet (165 g/L SouthlandMultiple Species Diet, 14.48 g/L agar) was prepared and dispensed to 128well trays, 500 ul per well. Samples were dispensed over the diet andplaced in a “dry down” chamber at 27C and 35% humidity, where excesswater is evaporated off. Once dried each well was infested with a singleneonate larva and sealed with a perforated mylar seal. The trays wereincubated for six to eight days at 27C. By this time, the untreatedcontrol insects had depleted all of the diet in their respective wells.Fifty-well trays were prepared with 4 ml artificial diet per well, andall insects that had depleted their diet, or were in danger of depletingit before the assay concluded, were transferred to the new trays. Thesetrays were sealed and returned to the incubator. The trays wereevaluated after ten to twelve days.

The results from these bioassays for the lepidopteran insect speciesindicate significant effect on larval mortality or mass gain has notbeen observed when compared to the untreated check (comparisons for allpairs using Tukey-Kramer HSD) using this assay regimen. More bioassaysare underway.

The FAW dsRNA sample was also tested in bioassay against FAW larvae incombination with a sub-lethal concentration of purified Cry1Ac proteinto test whether the ion channel- and pore forming-activity of thisinsect toxin could facilitate the uptake of dsRNA by midgut epithelialcells.

The results from these bioassays for FAW indicate significant effect ofthe Cry1Ac-dsRNA mixture on larval mortality or mass gain has not beenobserved when compared to the untreated check (comparisons for all pairsusing Tukey-Kramer HSD) using this assay regimen. More bioassays areunderway.

Example 9

This example illustrates the oral toxicity of dsRNAs towards larvae ofthe cotton boll weevil, Anthonomus grandis.

Total RNA was isolated from larvae of the cotton boll weevil (BWV),Anthonomus grandis, using the Ambion mirVana kit (Catalog # 1560) andrecommended procedures (Ambion Inc., Austin, Tex.). BWV larvae occupyingapproximately 200 ul volume in a microfuge tube were used for eachpreparation. Five micrograms of total RNA were used to prepare cDNAusing the Invitrogen Thermoscript™ RT-PCR system (Catalog # 11146) andrecommended procedures for random primer-mediated cDNA synthesis(Invitrogen, Carlsbad, Calif.). This cDNA was used as a template foramplification of V-ATPase A subunit 2 ortholog sequences using Taq DNApolymerase and the oligonucleotide primers pr 550 (SEQ ID NO:171) andpr552 (SEQ ID NO:172).

These primers were designed by aligning the nucleotide sequences for thenearest V-ATPase A orthologs from Manduca sexta, Aedes aegypti,Drosophila melanogaster, and Diabrotica virgifera (WCR) and selectingregions of minimal degeneracy. Primer pr550 corresponds to nucleotides230-252 in the M. sexta gene sequence while primer pr552 corresponds tonucleotides 1354-1331 in the M. sexta gene sequence.

Amplification was achieved using a touchdown amplification procedurewith the cycling parameters as described in Example 6. The approximately1.2 kb DNA fragment amplified from the cDNA was cloned into the vectorpCR2.1-TOPO (Invitrogen) and the insert sequenced for confirmation. TheV-ATPase A ortholog sequence (SEQ ID NO:160) was amplified using primerspr568 (SEQ ID NO:173) and pr569 (SEQ ID NO:174), designed as “universal”primers for generating DNA templates with flanking T7 polymerasepromoter sequences from pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) were synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

For bioassays of the boll weevil, Anthonomus grandis Boheman, anagar-based artificial insect diet was used (Bioserv™-F9247B; Gast andDavich, 1966) per manufacturers instructions. Approximately 200 ul ofmolten diet was dispensed into 96-well microtiter plates and allowed tocool and solidify. Sample (20 ul) was then overlaid onto the diet andallowed to dry. Insect eggs (0-14) in 25 ul of 0.1% agar were thendispensed onto the diet and the agar allowed to dry. The plates werethen sealed with perforated seals (Zymark #72281). The assay wasincubated at 27° C. for ten to twelve days and scored for activity bydetermination of frass accumulation.

Other target gene sequences from the boll weevil may be cloned and usedas templates for the in vitro synthesis of dsRNAs that can then betested in insect bioassay to assess their efficacy. For instance, theribosomal protein L19 (rpl19) gene may be used as a template for dsRNAsynthesis. The nucleotide sequences for the rpl19 orthologs from Bombyxmori (SEQ ID NO:165), Drosophila melanogaster (SEQ ID NO:166), Anopholesgambiae (SEQ ID NO:167), and Diabrotica virgifera (SEQ ID NO:168) werealigned and consensus regions of minimal degeneracy identified for thepurpose of designing degenerate oligonucleotide primers. Primers pr574(SEQ ID NO:177) and pr577 (SEQ ID NO:179) or primers pr575 (SEQ IDNO:178) and pr577 (SEQ ID NO:179) may be used to amplify putative rpl19ortholog sequences from many different insect species.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 6. The approximately 0.4kb DNA fragment amplified from the boll weevil cDNA was cloned into thevector pCR2.1-TOPO (Invitrogen) and the insert sequenced forconfirmation. The rpl19 ortholog sequence (SEQ ID NO:169) was amplifiedusing primers pr568 (SEQ ID NO:173) and pr569 (SEQ ID NO:174), designedas “universal” primers for generating DNA templates with flanking T7polymerase promoter sequences from pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) were synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Example 10

This example illustrates the oral toxicity of dsRNAs towards larvae ofthe red flour beetle, Tribolium castaneum.

Total RNA was isolated from larvae of the red flour beetle (RFB),Tribolium castaneum, using the Ambion mirVana kit (Catalog # 1560) andrecommended procedures (Ambion Inc., Austin, Tex.). RFB larvae occupyingapproximately 200 ul volume in a microfuge tube were used for eachpreparation. Five micrograms of total RNA were used to prepare cDNAusing the Invitrogen Thermoscript™ RT-PCR system (Catalog # 11146) andrecommended procedures for random primer-mediated cDNA synthesis(Invitrogen, Carlsbad, Calif.). This cDNA was used as a template foramplification of V-ATPase A subunit 2 ortholog sequences using Taq DNApolymerase and the oligonucleotide primers pr 550 (SEQ ID NO:171) andpr552 (SEQ ID NO:172).

These primers were designed by aligning the nucleotide sequences for thenearest V-ATPase A orthologs from Manduca sexta, Aedes aegypti,Drosophila melanogaster, and Diabrotica virgifera (WCR) and selectingregions of minimal degeneracy. Primer pr550 corresponds to nucleotides230-252 in the M. sexta gene sequence while primer pr552 corresponds tonucleotides 1354-1331 in the M. sexta gene sequence.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 6. The approximately 1.2kb DNA fragment amplified from the cDNA was cloned into the vectorpCR2.1-TOPO (Invitrogen) and the insert sequenced for confirmation. TheV-ATPase A ortholog sequence (SEQ ID NO:161) was amplified using primerspr568 (SEQ ID NO:173 and pr569 (SEQ ID NO:174), designed as “universal”primers for generating DNA templates with flanking T7 polymerasepromoter sequences from pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) were synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Other target gene sequences from the red flour beetle may be cloned andused as templates for the in vitro synthesis of dsRNAs that can then betested in insect bioassay to assess their efficacy. For instance, theribosomal protein L19 (rpl19) gene may be used as a template for dsRNAsynthesis. The nucleotide sequences for the rpl19 orthologs from Bombyxmori, Drosophila melanogaster, Anopholes gambiae, and Diabroticavirgifera were aligned and consensus regions of minimal degeneracyidentified for the purpose of designing degenerate oligonucleotideprimers. Primers pr574 (SEQ ID NO:177) and pr577 (SEQ ID NO:179) orprimers pr575 (SEQ ID NO:178) and pr577 (SEQ ID NO:179) may be used toamplify putative rpl19 ortholog sequences from many different insectspecies.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 6. The approximately 0.4kb kb DNA fragment amplified from the red flour beetle cDNA was clonedinto the vector pCR2.1-TOPO (Invitrogen) and the insert sequenced forconfirmation. The rpl19 ortholog sequence (SEQ ID NO:170) was amplifiedusing primers pr568 (SEQ ID NO:173) and pr569 (SEQ ID NO:174), designedas “universal” primers for generating DNA templates with flanking T7polymerase promoter sequences from pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) were synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Example 11

This example illustrates the oral toxicity of dsRNAs to white grubs andwireworms.

Total RNA is isolated from white grub of wireworm larvae using theAmbion mirVana kit (Catalog # 1560) and recommended procedures (AmbionInc., Austin, Tex.). Larvae occupying approximately 200 ul volume in amicrofuge tube are used for each preparation. Five micrograms of totalRNA are used to prepare cDNA using the Invitrogen Thermoscript™ RT-PCRsystem (Catalog # 11146) and recommended procedures for randomprimer-mediated cDNA synthesis (Invitrogen, Carlsbad, Calif.). This cDNAis used as a template for amplification of V-ATPase A subunit 2 orthologsequences using Taq DNA polymerase and the oligonucleotide primers pr550 (SEQ ID NO:171) and pr552 (SEQ ID NO:172).

These primers were designed by aligning the nucleotide sequences for thenearest V-ATPase A orthologs from Manduca sexta, Aedes aegypti,Drosophila melanogaster, and Diabrotica virgifera (WCR) and selectingregions of minimal degeneracy. Primer pr550 corresponds to nucleotides230-252 in the M. sexta gene sequence while primer pr552 corresponds tonucleotides 1354-1331 in the M. sexta gene sequence.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 7. The approximately 1.2kb DNA fragment amplified from the cDNA is cloned into the vectorpCR2.1-TOPO (Invitrogen) and the insert sequenced for confirmation. TheV-ATPase A ortholog sequence is amplified using primers pr568 (SEQ IDNO:173) and pr569 (SEQ ID NO:174), designed as “universal” primers forgenerating DNA templates with flanking T7 polymerase promoter sequencesfrom pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) are synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Other target gene sequences from white grubs or wireworms may be clonedand used as templates for the in vitro synthesis of dsRNAs that can thenbe tested in insect bioassay to assess their efficacy. For instance, theribosomal protein L19 (rpl19) gene may be used as a template for dsRNAsynthesis. The nucleotide sequences for the rpl19 orthologs from Bombyxmori, Drosophila melanogaster, Anopholes gambiae, and Diabroticavirgifera were aligned and consensus regions of minimal degeneracyidentified for the purpose of designing degenerate oligonucleotideprimers. Primers pr574 and pr577 or primers pr575 and pr577 may be usedto amplify putative rpl19 ortholog sequences from many different insectspecies.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 7. The approximately 0.4kb DNA fragment amplified from the cDNA is cloned into the vectorpCR2.1-TOPO (Invitrogen) and the insert sequenced for confirmation. Therpl19 ortholog sequence is amplified using primers pr568 (SEQ ID NO:173)and pr569 (SEQ ID NO:174), designed as “universal” primers forgenerating DNA templates with flanking T7 polymerase promoter sequencesfrom pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) are synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Example 12

This example illustrates the oral toxicity of dsRNAs towards larvae ofthe mosquito, Aedes aegypti.

Total RNA is isolated from larvae of Aedes aegypti larvae using theAmbion mirVana kit (Catalog # 1560) and recommended procedures (AmbionInc., Austin, Tex.). Aedes aegypti larvae occupying approximately 200 ulvolume in a microfuge tube are used for each preparation. Fivemicrograms of total RNA are used to prepare cDNA using the InvitrogenThermoscript™ RT-PCR system (Catalog # 11146) and recommended proceduresfor random primer-mediated cDNA synthesis (Invitrogen, Carlsbad,Calif.). This cDNA is used as a template for amplification of V-ATPase Asubunit 2 ortholog sequences using Taq DNA polymerase and theoligonucleotide primers pr 550 (SEQ ID NO:171) and pr552 (SEQ IDNO:172).

These primers were designed by aligning the nucleotide sequences for thenearest V-ATPase A orthologs from Manduca sexta, Aedes aegypti,Drosophila melanogaster, and Diabrotica virgifera (WCR) and selectingregions of minimal degeneracy. Primer pr550 corresponds to nucleotides230-252 in the M. sexta gene sequence while primer pr552 corresponds tonucleotides 1354-1331 in the M. sexta gene sequence.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 7. The approximately 1.2kb DNA fragment amplified from the cDNA is cloned into the vectorpCR2.1-TOPO (Invitrogen) and the insert sequenced for confirmation. TheV-ATPase A ortholog sequence is amplified using primers pr568 (SEQ IDNO:173) and pr569 (SEQ ID NO:174), designed as “universal” primers forgenerating DNA templates with flanking T7 polymerase promoter sequencesfrom pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) are synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Other target gene sequences from mosquitoes may be cloned and used astemplates for the in vitro synthesis of dsRNAs that can then be testedin insect bioassay to assess their efficacy. For instance, the ribosomalprotein L19 (rpl19) gene may be used as a template for dsRNA synthesis.The nucleotide sequences for the rpl19 orthologs from Bombyx mori,Drosophila melanogaster, Anopholes gambiae, and Diabrotica virgiferawere aligned and consensus regions of minimal degeneracy identified forthe purpose of designing degenerate oligonucleotide primers. Primerspr574 and pr577 or primers pr575 and pr577 may be used to amplifyputative rpl19 ortholog sequences from many different insect species.

Amplification is achieved using a touchdown amplification procedure withthe cycling parameters as described in Example 7. The approximately 0.4kb DNA fragment amplified from the cDNA is cloned into the vectorpCR2.1-TOPO (Invitrogen) and the insert sequenced for confirmation. Therpl19 ortholog sequence is amplified using primers pr568 (SEQ ID NO:173)and pr569 (SEQ ID NO:174), designed as “universal” primers forgenerating DNA templates with flanking T7 polymerase promoter sequencesfrom pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) are synthesized from this amplified DNAtemplate using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Other mosquito species are the subject of this invention. Suitabletarget gene sequences from Aedes, Culex, and Anopholes species can beamplified using appropriate oligonucleotide primers, cloned into thevector pCR2.1-TOPO (Invitrogen) and the insert sequenced forconfirmation. The cloned target sequences are amplified using primerspr568 (SEQ ID NO:173) and pr569 (SEQ ID NO:174), designed as “universal”primers for generating DNA templates with flanking T7 polymerasepromoter sequences from pCR2.1-TOPO clones.

Double-stranded RNAs (dsRNAs) are synthesized from these amplified DNAtemplates using the Ambion MEGAscript™ kit (Catalog # 1626) andrecommended procedures (Ambion Inc., Austin, Tex.) and submitted forinsect bioassay at 10 ppm.

Example 13

This example illustrates how dsRNA made from the 3′UTR region ofV-ATPase showed the down regulation of the target.

Segments (ca. 300 bp of dsRNA) of the WCR V-ATPase 3′ UTR have been putinto WCR bio-assay and failed to show stunting and mortality within a 12day bio-assay period. Comparably sized segments within the coding regionof the V-ATPase do show significant stunting and mortality at a range ofconcentrations. Northern blots examining total RNA extracted from WCRlarvae fed for 4 days on a V-ATPase 3′ UTR segment (and probed with acoding region probe) showed a significant decline in the V-ATPase targetmRNA relative to untreated control larvae (summarized NBP#7497215).However, detectable message remained, indicating less effectiveknock-down of the target with a 3′ UTR dsRNA segment (vs using a codingregion segment) and/or contribution from a putative second V-ATPase genethat has a significantly diverged 3′ UTR from the primary V-ATPase gene.Southern blot data on WCR is consistent with more than one hybridizinggene sequence within the genome, but examination of ESTs and limitedfamily PCR have not yet demonstrated that a putative second gene istranscribed.

It is important to mention that although it is critical to determine thepotential to stunt and kill larvae, simply monitoring expression of atarget gene by Northern blot or quantitative PCR could also find targetsamenable to RNAi strategies. The results above plus other northernexperiments looking at the V-ATPase target have shown that the RNAeffect on transcript abundance is discernable in insects within hours ofpresentation of the dsRNA.

Example 14

This example illustrates one approach to implementing insect pest genesuppression using a ta-siRNA mediated silencing method.

An alternative method to silence genes in a plant pest uses the recentlydiscovered class of trans-acting small interfering RNA (ta-siRNA)(Dalmay et al., Cell 101:543-553, 2000; Mourrain et al., Cell101:533-542, 2000; Peragine et al, Genes and Development, 18:2368-2379,2004; Vazquez et al, Mol Cell 16(1):69-79, 2004; Yu et al., Mol PlantMicrobe Interact 16:206-216, 2003). ta-siRNA are derived from singlestrand RNA transcripts that are targeted by naturally occurring mRNAwithin the cell. Methods for using microRNA to trigger ta-siRNA for genesilencing in plants are described in U.S. Provisional Patent ApplicationSer. No. 60/643,136 (Carrington et al. 2004), incorporated herein byreference in its entirety. At least one pest specific mRNA expressed ingut epithelial cells of corn rootworm larvae is identified. This pestspecific mRNA is then used to identify at least one target RNAtranscript sequence complementary to the mRNA that is expressed in thecell. The corresponding target sequence is a short sequence of no morethan 21 contiguous nucleotides that, when part of a RNA transcript andcontacted by its corresponding mRNA in a cell type with a functionalRNAi pathway, leads to slicer-mediated cleavage of said transcript. OncemRNA target sequences are identified, at least one mRNA target sequenceis fused to a second sequence that corresponds to part of a pest genethat is to be silenced using this method. For example, the mRNA targetsequence(s) is fused to sequences of the corn rootworm vacuolar ATPase(V-ATPase) gene. The mRNA target sequence can be placed at the 5′ end,the 3′ end, or embedded in the middle of the V-ATPase gene. It may bepreferable to use multiple mRNA target sequences corresponding tomultiple mRNA genes, or use the same mRNA target sequence multiple timesin the chimera of the mRNA target sequence and the V-ATPase sequence.The V-ATPase sequence can be of any length, with a minimum of 21 bp.

The chimera of the mRNA target sequence(s) and the V-ATPase sequence isexpressed in plant cells using any of a number of appropriate promoterand other transcription regulatory elements, as long as thetranscription occurs in cells types subject to being provided in thediet of the pest, e.g. corn roots for control of corn rootworm.

This method may have the additional advantage of delivering longer RNAmolecules to the target pest. Typically, dsRNA's produced in plants arerapidly processed by Dicer into short RNA's that may not be effectivewhen fed exogenously to some pests. In this method, a single strandtranscript is produced in the plant cell, taken up by the pest, andconverted into a dsRNA in the pest cell where it is then processed intota-siRNA capable of post-transcriptionally silencing one or more genesin one or more target pests.

Example 15

This example illustrates how the DNA sequence conservation analysis wasperformed. cDNA sequences that are conserved between two organisms arepotential RNAi candidates that can be used to target the gene expressionand function of both organisms. The same is true if the conservationoccurs in more than two organisms. The conversation analysis was toidentify the conserved cDNA sequence segments between Lygus and cornrootworm (CRW), and other organisms in Insecta order.

Six cDNA sequences from CRW were selected for the analysis and they werethose that encoded alpha-tubulin, beta-tubulin, CHD3, vacuolar protonpump E subunit, V-ATPase A subunit and thread proteins, the nucleotidesequences of which are as set forth in SEQ ID NO:109, SEQ ID NO:110, SEQID NO:111, SEQ ID NO:112, SEQ ID NO:113 and SEQ ID NO:114, respectively.Lygus homologs of the 6 CRW were identified from the Lygus Unigenedataset. The homologs were defined as the most significant matches tothe 6 CRW sequences, as indicated by the best expectation value of NCBIBlast searches. The lygus cDNA sequences were then matched to the cDNAsequence database containing all public cDNAs of various organisms fromGenBank. This was done with NCBI megablast program (Altschul et al., J.Mol. Biol. 215:403-410, 1990) with the following parameters:

-   -   —W 21-b50-v50        where at least a 21-mer perfect match was required, and the top        50 matches and alignments were kept.

The results were further filtered to include only organisms in Insectaorder, and honey bee (Apis mellifera) was excluded. Although theanalysis was only done on the six lygus cDNA sequences, the same processmay be applied to all cDNA or Unigene sequences in lygus or otherorganism of interest.

Using the 6 Lygus homologs, 92 matches were identified with a minimum of21-mer perfect match region, from 16 distinct organisms, includingseveral pest species, such as Toxoptera citricida (brown citrus aphid).

The results are presented in Table 4 below with coordinates of match onthe query sequence and the hit, percent identity of the match, and theinsect species from which the hit sequence was derived. For example, asegment from nucleotide position 312-1575 in SEQ ID NO:180 wasidentified to be substantially identical to a segment from nucleotideposition 184 to 1447 from a GenBank sequence with the accession numberGI: 46409239 from pea aphid (Acyrthosiphon pisum). TABLE 4 Lygus UnigeneSequences and Insect Nucleotide Sequence Homologs SEQ ID NO¹ Position²Gene ID³ Position⁴ % Identity⁵ Genus species⁶ Seq ID No: 180  312-1575GI: 46409239  184-1447 84% Drosophila melanogaster Seq ID No: 180 312-1575 GI: 24644733  259-1522 84% Drosophila melanogaster Seq ID No:180  312-1575 GI: 19523  196-1459 84% Drosophila melanogaster Seq ID No:180  312-1575 GI: 17136563  55-1318 84% Drosophila melanogaster Seq IDNo: 181 1409-2739 GI: 39842328 1346-16  83% Laodelphax striatellus SeqID No: 181 1436-2280 GI: 24655740 1507-663  86% Drosophila melanogasterSeq ID No: 181 1436-2280 GI: 28573699 1349-505  86% Drosophilamelanogaster Seq ID No: 181 1436-2280 GI: 24655745 1316-472  86%Drosophila melanogaster Seq ID No: 181 1436-2280 GI: 24655736 1447-603 86% Drosophila melanogaster Seq ID No: 181 1436-2280 GI: 184852531447-603  86% Drosophila melanogaster Seq ID No: 181 1436-2280 GI:27819908 1447-603  86% Drosophila melanogaster Seq ID No: 181 1436-2280GI: 17647196 1319-475  86% Drosophila melanogaster Seq ID No: 1811436-2280 GI: 158738 1319-475  86% Drosophila melanogaster Seq ID No:181 1436-2280 GI: 33354948 851-5  85% Drosophila yakuba Seq ID No: 1811412-2301 GI: 2613140 1414-525  85% Manduca sexta Seq ID No: 1812426-2756 GI: 2613140 400-70  84% Manduca sexta Seq ID No: 181 1411-2301GI: 19773427 1415-525  84% Bombyx mori Seq ID No: 181 2396-2756 GI:19773427 430-70  84% Bombyx mori Seq ID No: 181 1411-2301 GI: 33997231436-546  84% Bombyx mori Seq ID No: 181 1535-2280 GI: 38047746 752-7 85% Drosophila yakuba Seq ID No: 181 1436-1989 GI: 55690054  68-621 88%Drosophila yakuba Seq ID No: 181 1454-2175 GI: 29534763 746-25  84%Bombyx mori Seq ID No: 181 1460-2303 GI: 54650593 1512-669  83%Drosophila melanogaster Seq ID No: 181 2662-2754 GI: 54650593 292-20088% Drosophila melanogaster Seq ID No: 181 1460-2303 GI: 220240301513-670  83% Drosophila melanogaster Seq ID No: 181 2662-2754 GI:22024030 293-201 88% Drosophila melanogaster Seq ID No: 181 1436-1946GI: 38623309 167-677 88% Drosophila melanogaster Seq ID No: 1811436-2303 GI: 58377631 1274-407  83% Anopheles gambiae str. Seq ID No:181 1436-2303 GI: 31201634 1334-467  83% Anopheles gambiae str. Seq IDNo: 181 1436-1956 GI: 26256234 190-711 88% Drosophila melanogaster SeqID No: 181 1436-1890 GI: 4422454 167-621 89% Drosophila melanogaster SeqID No: 181 1436-1890 GI: 18485251 458-4  89% Drosophila melanogaster SeqID No: 181 1411-1979 GI: 40928273 588-18  86% Bombyx mori Seq ID No: 1811436-1896 GI: 3113758 179-640 89% Drosophila melanogaster Seq ID No: 182437-742 GI: 58394107 5390-5085 83% Anopheles gambiae str. Seq ID No: 182437-742 GI: 31240218 5582-5277 83% Anopheles gambiae str. Seq ID No: 182317-738 GI: 21351846 5734-5313 80% Drosophila melanogaster Seq ID No:182 317-738 GI: 4325129 5734-5313 80% Drosophila melanogaster Seq ID No:182 169-471 GI: 40948248 346-42  79% Bombyx mori Seq ID No: 182 169-471GI: 40870266 314-10  79% Bombyx mori Seq ID No: 182 1072-1092 GI:42762503 436-416 100% Aedes aegypti Seq ID No: 183 102-337 GI: 60296136 53-288 85% Homalodisca coagulata Seq ID No: 183 102-337 GI: 46561759 1-236 85% Homalodisca coagulata Seq ID No: 183 102-370 GI: 16901350 70-338 83% Ctenocephalides felis Seq ID No: 183 102-370 GI: 16900951 78-346 83% Ctenocephalides felis Seq ID No: 183 102-337 GI: 50558386 54-290 84% Homalodisca coagulata Seq ID No: 183 102-337 GI: 47518467119-354 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 47522193101-336 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 47521069 86-321 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 47521063112-347 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 47519475104-339 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 47518488110-345 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 46997557 88-323 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 46997022 84-319 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 46996748 77-312 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 46995965111-346 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 46995786 86-321 83% Acyrthosiphon pisum Seq ID No: 183 102-337 GI: 46994074106-341 83% Acyrthosiphon pisum Seq ID No: 183 138-373 GI: 31366354 11-246 83% Toxoptera citricida Seq ID No: 183  99-232 GI: 41578101126-259 89% Culicoides sonorensis Seq ID No: 183  99-232 GI: 41577171 67-200 89% Culicoides sonorensis Seq ID No: 184  780-1884 GI: 11061 759-1863 82% Manduca sexta Seq ID No: 184 128-276 GI: 11061 110-258 85%Manduca sexta Seq ID No: 184  756-1257 GI: 2454487  827-1328 85% Aedesaegypti Seq ID No: 184 1662-1690 GI: 2454487 1733-1761 100% Aedesaegypti Seq ID No: 184  782-1245 GI: 24583987  848-1311 85% Drosophilamelanogaster Seq ID No: 184 1292-1563 GI: 24583987 1358-1629 83%Drosophila melanogaster Seq ID No: 184  782-1245 GI: 24583985  760-122385% Drosophila melanogaster Seq ID No: 184 1292-1563 GI: 245839851270-1541 83% Drosophila melanogaster Seq ID No: 184  782-1245 GI:24583983  845-1308 85% Drosophila melanogaster Seq ID No: 184 1292-1563GI: 24583983 1355-1626 83% Drosophila melanogaster Seq ID No: 184 782-1245 GI: 19527546  845-1308 85% Drosophila melanogaster Seq ID No:184 1292-1563 GI: 19527546 1355-1626 82% Drosophila melanogaster Seq IDNo: 184  756-1221 GI: 4734043 182-647 85% Aedes aegypti Seq ID No: 184 782-1245 GI: 21355198  787-1250 84% Drosophila melanogaster Seq ID No:184  782-1245 GI: 1373432  787-1250 84% Drosophila melanogaster Seq IDNo: 184  782-1128 GI: 49361366  40-386 86% Drosophila melanogaster SeqID No: 184  916-1245 GI: 3514814  1-330 85% Drosophila melanogaster SeqID No: 184  785-1137 GI: 31207752  825-1177 84% Anopheles gambiae str.Seq ID No: 184  905-1335 GI: 33376955  15-445 82% Glossina morsitansmorsitans Seq ID No: 184  905-1255 GI: 33376948  10-360 83% Glossinamorsitans morsitans Seq ID No: 184  817-1053 GI: 22005558  58-294 86%Aedes aegypti Seq ID No: 184 1353-1716 GI: 33528180 165-528 81%Trichoplusia ni Seq ID No: 184 1292-1563 GI: 13691260 202-473 82%Drosophila melanogaster Seq ID No: 184 1292-1563 GI: 11582697 211-48282% Drosophila melanogaster Seq ID No: 184 1352-1704 GI: 22474258 21-373 81% Helicoverpa armigera Seq ID No: 184 185-384 GI: 56772924141-340 84% Drosophila virilis Seq ID No: 184 1292-1530 GI: 245839911368-1606 83% Drosophila melanogaster Seq ID No: 184 1292-1530 GI:18467977 1368-1606 83% Drosophila melanogaster Seq ID No: 184 1292-1530GI: 19528270 1308-1546 83% Drosophila melanogaster Seq ID No: 1841292-1530 GI: 18859618 1238-1476 83% Drosophila melanogaster Seq ID No:184 1292-1530 GI: 5851682 1308-1546 83% Drosophila melanogaster¹Lygus SEQ ID NO as set forth in the Sequence Listing;²Nucleotide position in the SEQ ID NO in column 1 that matches withposition of sequence of Gene ID in column 3 on same row;³Gene ID number of corresponding matching sequence hit from publicdatabase that matches with position of SEQ ID No from column 1;⁴Gene ID nucleotide position in column 3 that matches with nucleotidesspecified on same row corresponding to sequence of Lygus SEQ ID NO;⁵Percentage identity between the two sequences in Lygus SEQ ID NO andGene ID (comparison of identity between column 2 and column 4sequences); and⁶Genus and species of organism corresponding to the gene sequence setforth in Column 3.

Example 16

This example illustrates a method for providing a DNA sequence fordsRNA-mediated gene silencing. More specifically, this example describesselection of an improved DNA useful in dsRNA-mediated gene silencing by(a) selecting from a target gene an initial DNA sequence including morethan 21 contiguous nucleotides; (b) identifying at least one shorter DNAsequence derived from regions of the initial DNA sequence consisting ofregions predicted to not generate undesirable polypeptides; and (c)selecting a DNA sequence for dsRNA-mediated gene silencing that includesthe at least one shorter DNA sequence. Undesirable polypeptides include,but are not limited to, polypeptides homologous to allergenicpolypeptides and polypeptides homologous to known polypeptide toxins.

WCR V-ATPase has been demonstrated to function in corn rootworm feedingassays to test dsRNA mediated silencing as a means of controlling larvalgrowth. A cDNA sequence from a vacuolar ATPase gene (V-ATPase) fromWestern corn rootworm (WCR) (Diabrotica virgifera virgifera LeConte) wasselected for use as an initial DNA sequence (SEQ ID NO:115). Thisinitial DNA sequence was screened for regions within which everycontiguous fragment including at least 21 nucleotides matched fewer than21 out of 21 contiguous nucleotides of known vertebrate sequences. Threesequence segments greater than about 100 contiguous nucleotides thatwere free of such 21/21 hits were identified; a first sequence segmentcorresponding to nucleotide position 739-839, a second sequence segmentcorresponding to nucleotide position 849-987, and a third sequencesegment corresponding to nucleotide position 998-1166 as set forth inSEQ ID NO:115. These three sequence segments were combined to constructa chimeric DNA sequence (SEQ ID NO:1) for use in dsRNA-mediated genesilencing of the corresponding CRW V-ATPase coding sequence. The novelchimeric DNA sequence was tested in the CRW bioassay described above.

In summary, the above specification describes preferred embodiments ofthe present invention. It will be understood by those skilled in the artthat, without departing from the scope and spirit of the presentinvention and without undue experimentation, the present invention canbe performed within a wide range of equivalent parameters. While thepresent invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodifications. The present invention is intended to cover any uses,variations, or adaptations of the invention following the principles ofthe invention in general. Various permutations and combination of theelements provided in all the claims that follow are possible and fallwithin the scope of this invention.

All publications, patents and published patent applications mentioned inthis specification are herein incorporated by reference as if eachindividual publication or patent was specially and individually statedto be incorporated by reference.

1. A method for controlling a lygus pest infestation comprisingproviding in the diet of a lygus pest an agent comprising a ribonucleicacid that functions upon ingestion by the pest to inhibit the expressionof a target sequence within said pest, wherein said ribonucleic acidconsists of a ribonucleotide sequence that is or is complementary tosaid target sequence, wherein said ribonucleotide sequence istranscribed from a DNA sequence selected from the group consisting ofSEQ ID NO:4 through SEQ ID NO:14, SEQ ID NO:180 through SEQ ID NO:184,and the complement thereof.
 2. The method of claim 1 wherein said lyguspest is selected from the group consisting of a Lygus hesperus and Lyguslineolori.
 3. A method for inhibiting expression of a target nucleotidesequence in a lygus plant pest comprising providing in the diet of saidpest an agent that, upon ingestion by said pest, inhibits the expressionof a nucleotide sequence in said pest, said agent comprising aribonucleic acid expressed from a DNA sequence that is from about 80 toabout 100% identical to a nucleotide coding sequence present in saidpest, said nucleotide coding sequence being selected from the groupconsisting of SEQ ID NO:4 through SEQ ID NO:14, SEQ ID NO:180 throughSEQ ID NO:184, and the complement thereof.
 4. A polynucleotidecomposition for use in a plant cell comprising an expression cassettecomprising a plant functional promoter operably linked to a nucleotidesequence element comprising from about 50 to about 5000 contiguousnucleotides exhibiting from about 80 to about 100% sequence identity toa nucleotide coding sequence selected from the group consisting of SEQID NO:4 through SEQ ID NO:14, SEQ ID NO:180 through SEQ ID NO:184, andthe complement thereof, wherein ingestion of said polynucleotidecomposition by a lygus plant pest inhibits an essential biologicalfunction in said pest.
 5. A plant cell comprising the polynucleotidecomposition of claim 4, a plant regenerated from the plant cell, aprogeny plant produced from the regenerated plant, wherein said progenyplant comprises said polynucleotide composition, and a seed producedfrom the progeny plant, wherein said seed comprises said polynucleotidecomposition.
 6. A method for inhibiting the expression of a target geneproduct in one or more cells of a lygus insect pest comprising providingto said one or more cells a gene suppressive amount of an RNA moleculein the diet of said insect, wherein said gene suppressive RNA moleculeis produced from a DNA sequence selected from the group consisting ofSEQ ID NO:4 through SEQ ID NO:14, SEQ ID NO:180 through SEQ ID NO:184,and the complement thereof, said ingestion of said gene suppressive RNAresulting in a decrease in the level of said target gene product in saidinsect pest cell.
 7. The method of claim 6 wherein said lygus pest isselected from the group consisting of a Lygus hesperus and Lyguslineolori.
 8. A method for controlling lygus insect pest infestationcomprising providing in the diet of a lygus insect pest an agentcomprising a first ribonucleotide sequence that functions upon ingestionby the pest to inhibit a biological function within said pest, whereinsaid ribonucleotide sequence exhibits from about 95 to about 100%nucleotide sequence identity along at least from about 14 to about 25contiguous nucleotides to a coding sequence derived from said pest andis hybridized to a second ribonucleotide sequence that is complementaryto said first ribonucleotide sequence, and wherein said coding sequencederived from said pest is selected from the group consisting of SEQ IDNO:4 through SEQ ID NO:14, SEQ ID NO:180 through SEQ ID NO:184, and thecomplement thereof.
 9. The method of claim 8, wherein said diet isselected from the group consisting of an artificial diet, a plant cell,a plurality of plant cells, a plant tissue, a plant root, a plant seed,and a plant grown from a plant seed, wherein said diet comprises a pestinhibitory amount of said RNA molecule.